United Left Izquierda Unida
General Coordinator	Antonio Maíllo
Founded	April 1986 (as coalition) 2 November 1992 (as party federation)
Youth wing	Área de Juventud de Izquierda Unida
LGBT wing	ALEAS
Membership (2023)	18,000[1]
Ideology	Communism[2] Socialism[2] Republicanism[3]
Political position	Left-wing[6] to far-left[9]
National affiliation	The Left (2009–2014) Plural Left (2011–2015) Plural Left (2014–2019) Popular Unity (2015–2016) Unidas Podemos (2016–2023) Sumar (since 2023)
European affiliation	Party of the European Left
International affiliation	IMCWP
Colours	Red
Congress of Deputies	5 / 350
Spanish Senate	0 / 266
European Parliament	0 / 61
Regional Parliaments	10 / 1,268
Local Government	1,678 / 67,515
Website
izquierda-unida.es
Politics of Spain Political parties Elections

United Left (Spanish: Izquierda Unida [iθˈkjeɾðawˈniða], IU) is a federative political movement in Spain that was first organized as a coalition in 1986, bringing together several left-wing political organizations, grouped primarily around the Communist Party of Spain.^[10]

IU was founded as an electoral coalition of seven parties, but the Communist Party of Spain (PCE) is the only remaining integrated member of the IU at the national level.^[10] Despite that, IU brings together other regional parties, political organizations, and independents.^[10] It currently takes the form of a permanent federation of parties.

IU took part in the Unidas Podemos coalition and the corresponding parliamentary group in the Congreso de los Diputados between 2016 and 2023. Since January 2020, it participated for the first time in a national coalition government, with one minister. For the 2023 general election, IU took part in the Sumar platform.^[11]

Following the electoral failure of the PCE in the 1982 general election (going from 10% to 4% of the votes), PCE leaders believed that the PCE alone could no longer effectively challenge the electoral hegemony of the Spanish Socialist Workers' Party (PSOE) on the left.^[10] With this premise, the PCE began developing closer relations with other left-wing groups, with the vision of forming a broad left coalition.^[10] IU slowly improved its results, reaching 9% in 1989 (1,800,000 votes) and nearly 11% in 1996 (2,600,000 votes). The founding organizations were: Communist Party of Spain, Progressive Federation, Communist Party of the Peoples of Spain, PASOC, Carlist Party, Humanist Party, Unitarian Candidacy of Workers, and Republican Left.

In contrast to the PCE prior to the formation of IU, which pursued a more moderate political course, the new IU adopted a more radical strategy and ideology of confrontation against the PSOE.^[12][10] IU generally opposed cooperating with the PSOE, and identified it as a "right-wing party", no different from the People's Party (PP).^[12][10]

After achieving poor results in the 1999 local and European elections, IU decided to adopt a more conciliatory attitude towards the PSOE, and agreed to sign an electoral pact with the PSOE for the upcoming general election in 2000.^[10] They also adopted a universal policy in favor of cooperating with the PSOE at the local level.^[10]

IU currently has around 18,000 members, a decrease from 70,000 in 2012.^[1][13]

The first organizational antecedent among the various left-wing parties that would later form United Left dates back to 13 February 1986, when an electoral coalition agreement was presented under the provisional name Left Alternative (Alternativa de la Izquierda), made up of the Progressive Federation and the Socialist Action Party, calling on the Communist Party to join the grouping.^[14] United Left (IU) was founded in the wake of the mobilizations demanding Spain's withdrawal from NATO in 1986, when the Civic Platform for Spain's Withdrawal from NATO (Plataforma Cívica por la Salida de España de la OTAN) – chaired by the writer Antonio Gala – managed to bring together almost all of the country's left-wing organizations. Many of those organizations later joined the coalition "United Left Platform" (Plataforma de la Izquierda Unida).^[15] On 12 March 1986 a referendum was held, whose result favored remaining in NATO, although there were nearly seven million votes against.

The first meeting of the coalition took place on 27 April 1986 in the office of the lawyer Cristina Almeida, and included the participation of the Communist Party of Spain (PCE), the Unified Socialist Party of Catalonia (PSUC), the Socialist Action Party (PASOC), Republican Left (IR), the Progressive Federation (FP), the Humanist Party, and the Carlist Party.^[16] These parties would later be joined by the Communist Party of the Peoples of Spain (PCPE) and the Workers' Unity Collective-Andalusian Left Bloc (CUT-BAI), as well as a number of independent politicians. A Political Commission was formed to govern it, chaired by Gerardo Iglesias, secretary general of the PCE – a party that made up 80% of the coalition. On 29 April the coalition was officially constituted.^[17]

In June 1986, IU participated for the first time in a general election, winning seven seats (three more than the PCE in the previous general election) with 4.6% of the vote. In the 1987 municipal elections its results improved, winning 7.18% of the vote. However, that same year the Humanist Party was expelled from IU, among other reasons because of its connections with an Argentine sect known as La Comunidad.^[18] The Carlist Party was also expelled from the coalition.^[19] The Progressive Federation would end up leaving IU in 1987 and dissolved a year later, in 1988.

Up to that date, IU had run in elections with a symbol that included the logos of the PCE, PASOC, PCPE and FP,^[20][21] but in 1988 it called a public competition to design a new logo. The result was a symbol with the I and the U in gray and green with a touch of red, with significant variations depending on the region where the candidacy was presented, incorporating regional flags or icons and changes in the initials or even entirely different marks, such as that of Ezker Batua in the Basque Country.^[22]

In January 1989 the PCPE also left the coalition, following the reincorporation into the PCE of its president and founder – Ignacio Gallego – together with eight thousand militants, forty-eight members of the Central Committee and the majority of public officeholders. In February 1989 the 1st General Assembly was held, where, deciding to abandon the coalition organizational model, IU approved its new self-definition as a "political and social movement".^[23] Nearly a thousand delegates participated, of whom only 25% had been elected from among the parties integrated into the coalition, and the rest directly by members in the various autonomous communities. A Collegiate Presidency was elected – later called the Federal Presidency – which chose Gerardo Iglesias as federal coordinator.

In the 1989 general election, United Left had already become the third most-voted political force, reaching seventeen MPs with 9.07% of the vote.

In November 1989 Gerardo Iglesias resigned as secretary general of the PCE and as IU coordinator, and in the latter position he was replaced by Julio Anguita – mayor of Córdoba between 1979 and 1986, and a politician very well known at that time within the PCE. In November 1990 the 2nd Federal Assembly of IU was held, which confirmed Julio Anguita as coordinator, and which represented the transfer of sovereignty from the PCE and the other constituent parties to IU's own bodies. At that assembly it was agreed not to make pacts with the PSOE, considering that it had betrayed the "ideals of the left". However, the regional federations of Galicia, Catalonia and the Canary Islands had constituted themselves as autonomous, in order to seek their own agreements. In the case of Initiative for Catalonia – which had succeeded the PSUC – its leader Rafael Ribó advocated seeking "the common home of the left", by making pacts with the PSOE.

In August 1991, a group of leaders of the PCE and the PASOC, supported by the secretary general of Workers' Commissions (CCOO), Antonio Gutiérrez, backed turning IU into a political party by dissolving the forces that made it up, trusting that the 13th Congress of the PCE would be the last to be held, thus opposing Julio Anguita's thesis of maintaining party pluralism within the coalition.^[24][25] After the decision by Esquerra Unida del País Valencià to register as its own political party, a majority sector of IU's Presidency opted to support it and grant full autonomy to the territorial federations; Julio Anguita, by contrast, chose to refer the decision to the Federal Political Council, resigning in protest at what he considered a violation of the statutes.^[26] Ultimately, any dissolution of the PCE was rejected.^[27] Izquierda Canaria Unida (ICU), IU's first reference in the Canary Islands, was part of the Iniciativa Canaria Nacionalista (ICAN) coalition for a few months in 1991. The membership, dissatisfied with a project not federated with IU and "shifted to the right" – because of the pacts it signed with the PP – recovered the project of the PCE and of United Left in the Canary Islands in 1991 and 1992, respectively. Later, ICAN formed Canarian Coalition in 1993.

In 1992 Julio Anguita denounced what he saw as a PSOE and PP strategy to build a new two-party system, through a strategy of constant tension between the two parties, despite the fact that they shared the same economic model that generated corruption. Against this, Anguita defined what he called a "new way of doing politics".^[28] In IU's 3rd Assembly, held that same year, United Left debated the Maastricht Treaty in depth, deciding to oppose the European project it represented. Anguita was re-elected in the 3rd, 4th and 5th Federal Assemblies (1992, 1994, and 1997, respectively), although from 1992 onward he had to confront an organized critical current called "Democratic Party of the New Left" (Nueva Izquierda), of social-democratic tendency and supportive of the Third Way, which brought together part of the IU sectors outside the PCE. Numerically, New Left was a small sector, but it included prominent public officeholders and leaders – such as Nicolás Sartorius, Diego López Garrido, and Cristina Almeida – who appeared frequently in the media, and it largely favored consolidating IU as a political organization independent from the formations that created it, to transform it into a party that would collaborate closely with the PSOE.

In 1993 Julio Anguita announced a crisis of the state, since he believed the government of Felipe González (PSOE) was only "patching up" problems, betting on "profitable and fast" business, which led to corruption cases. He rejected precarious employment, company closures and the destruction of the industrial fabric, and highlighted the "major coincidences" between PSOE and People's Party proposals and the falsity of a situation centered on verbal confrontation between González and José María Aznar, "which brings to mind the two-party system of Cánovas and Sagasta".^[29]

IU's general coordinator developed the theory of "the two shores" and the "sorpasso": the PP and PSOE were on the right bank, with neoliberalism, and IU on the left bank, with the workers. He also rejected the philosophy of "leaders", considering that politics should be a collective task,^[30] as well as the "social pact" proposed by CCOO's new leadership with the government and employers' organizations.^[31] Also during this period, United Left became the first political organization in Spain to have an internal LGBT group, by creating ALEAS in 1994, an area devoted to the defense of affective-sexual freedoms.^[32]

In the 1995 municipal elections IU obtained 11.68% of the vote, which allowed several federations to reach governing pacts with the PSOE in many town councils, especially in southern Madrid and in Andalusia. That same year Alternative Left joined as an internal current, formed by former militants of the dissolved Revolutionary Communist League (LCR), and which would end up redefining itself as Espacio Alternativo. In 1996 IU held primary elections in which Julio Anguita was chosen as the head of the list for the next general election.^[33][34] In the March general election that year, IU surpassed 10% of the vote and managed to form a parliamentary group of 21 MPs, a result very similar to what the PCE had obtained in the 1970s.

Following the arrival to government of the People's Party, led by José María Aznar, tensions increased within IU. Anguita not only opposed the governing party, but also continued criticizing the PSOE and former prime minister Felipe González, for being mired in corruption and in policies contrary to his positions.

Tensions within IU continued until they had political consequences. On 25 May 1997 the national council of the Galician federation, Esquerda Unida-Esquerda Galega (EU-EG), decided – with state-level support from the Democratic Party of the New Left – to form a coalition with the PSdG in the regional election.^[35] The agreement, headed by the general coordinator, Anxo Guerreiro, was adopted against the decision taken at the EU-IU national conference, as well as against the secretary general of the Communist Party of Galicia (PCG). The federal leadership of United Left disavowed the coalition and sanctioned the MPs of the New Left current who supported it. On 15 June 1997 the Treball festival was held amid strong tensions between IU and Initiative for Catalonia (IC). Rafael Ribó, president of IC and secretary general of the PSUC, continued defending alliances with the PSOE and rejected IU's criticism of the trade unions CCOO and Unión General de Trabajadores (UGT) as well as the sanctions against the New Left MPs, by then already constituted as a party within IU. He also supported the Esquerda Unida-PSOE coalition, disavowed by IU's leadership. By contrast, Julio Anguita defended left unity only through specific programmatic criteria and by rejecting the corruption that affected the PSOE.^[36]

In 1997 the three IU MPs belonging to New Left broke away from the rest of the parliamentary group and refused to reject the labor reform that created the "open-ended employment promotion contract", which made dismissal cheaper compared with the ordinary contract.^[37] IU's Executive expelled New Left members from the leadership and asked them to give up their seats as MPs,^[38] after which they decided to remain in Congress under the name Democratic Party of the New Left (PDNI). In September that year IU held its 5th Federal Assembly amid a serious crisis. The New Left party was expelled, with its members joining the PSOE. The federations controlled by that current (specifically those of Castilla–La Mancha and Aragón) were dissolved. The leaders of IC and EU-EG, with their executive committees, were also expelled.^[39] Part of EU-EG held an assembly in which they decided to maintain their relationship with United Left at the federal level and to run in regional elections under the name "United Left". Later, the courts granted IU's Galician federation the use of the name Esquerda Unida, and supporters of the former coordinator Anxo Guerreiro constituted Left of Galicia, which ended up dissolving a few years later. Similarly, the IC sectors closest to IU's federal leadership left the party and formed PSUC viu, which would create, together with other parties, the coalition United and Alternative Left (EUiA), federated with IU.^[40] In December 1998 IU led demonstrations across the country after a year of mobilizing for a 35-hour workweek, with support from trade unions such as the General Confederation of Labour (CGT) or Unión Sindical Obrera (USO), as well as the critical sector of CCOO. By contrast, the leaderships of the major unions CCOO and UGT did not join. It was the start of a Popular Legislative Initiative that needed to collect 500,000 signatures to be launched.^[41] That year several organizations joined United Left: the Revolutionary Workers' Party (POR), the Revolutionary Party of the Workers (PRT), and Nueva Claridad, affiliated with the International Marxist Tendency.

In mid-1998, after reflecting on it and reaching agreement with other leaders, Julio Anguita resigned as secretary general of the PCE and was replaced by Francisco Frutos.^[42] Anguita argued at the time that the reason for his departure was his illness, although years later he acknowledged that this was only a pretext, because what had happened was that the defeat of the positions he defended had been consummated and he saw no point in continuing where he did not feel comfortable. He did not agree with a policy of "blank check" support for the PSOE or for CCOO at the trade-union level, since he believed action should be based on ideas and the program.^[43] Francisco Frutos had already held various positions in IU's leadership, as he had been number two on the list in the 1996 general election. Although he never became IU's federal coordinator, in January 2000 he was designated by the organization to lead its bid for the prime ministership in the 2000 general election.

During the 1999–2000 electoral cycle, EUiA and ICV would act separately, with ICV running in coalition with the PSC-PSOE in the 1999 Catalan regional election in several provinces. That same year, in Cantabria a split also occurred: Izquierda Democrática Cántabra (IDCAN), to which IU's three MPs in the Parliament of Cantabria at the time moved; this new formation subsequently ran in coalition with the Socialist Party of Cantabria (PSC-PSOE) until its integration into it in 2003. IU also changed its policy toward an approach to the PSOE, and signed a pre-electoral investiture agreement with the PSOE for the March 2000 general election. The result was a spectacular failure for both parties, and an absolute majority victory for the People's Party. United Left saw its support reduced to half, obtaining only 8 MPs with 5.45% of the vote.

At the end of that same year, Gaspar Llamazares was elected at the 6th Federal Assembly by a narrow margin over Francisco Frutos as federal coordinator, bringing together the votes of various IU currents critical of the outgoing leadership.

Gaspar Llamazares coordinated IU while leaning on the PSOE, with a policy of confrontation with the PCE, led by Francisco Frutos. At the Catalan level he restored relations with Initiative for Catalonia Greens (ICV), while at the same time maintaining United and Alternative Left (EUiA) as IU's formal reference in Catalonia. He likewise tried to imprint on IU an orientation more ecosocialist than communist or libertarian.^[44] In 2001, IU's then Basque federation, Ezker Batua (IU-EB), entered the Basque Government, making a pact with the conservative Basque Nationalist Party (PNV) and Eusko Alkartasuna (EA).

In 2001, Pablo Castellano left the PASOC presidency to Luis Aurelio Sánchez, and PASOC left IU due to disagreements with Llamazares' new policy, while a splinter group (later called Iniciativa Socialista de Izquierdas) remained within. On 2 March 2002 Republican Left also left the coalition,^[45] being unable to define a concrete political project within United Left, and Ángeles Maestro founded Corriente Roja within IU, representing the positions most critical of the leadership and closest to the Basque nationalist left (izquierda abertzale). In 2003 IU ran in the municipal and regional elections with Bloc for Asturias (BA), Independent Socialists of Extremadura (SIEX), and ICV, obtaining very negative results. Only the ICV-EUiA coalition in Catalonia and IU's Basque federation, Ezker Batua, increased their support. IU maintained an electorate slightly under one million voters, and a historical base of support in Catalonia, Asturias, Madrid, the Valencian Community, and Andalusia, due to the communist tradition in areas of those regions. It also maintained a special link with Spain's largest trade-union confederation, Comisiones Obreras (CCOO), of communist tradition during Francoism and the early years of the transition, with one million members.

In the 2004 general election, IU reduced the votes obtained, while turnout and PSOE votes increased considerably. As a consequence, it obtained only three MPs: Gaspar Llamazares, Ángel Pérez Martínez, and Isaura Navarro. In the Congress of Deputies, a parliamentary group was formed together with the two MPs from Initiative for Catalonia Greens–United and Alternative Left under the name Izquierda Verde–Izquierda Unida–Iniciativa per Catalunya Verds. A few months later, in the 2004 European election, United Left ran together with ICV, EUiA, Republican Left, Red Verde – a party formed mainly by former members of New Left – and other minor groups, achieving a vote share even lower than in the general election. Of the two MEPs obtained, one was from United Left (Willy Meyer) and the other from Initiative for Catalonia Greens (Raül Romeva), who once elected joined the European Green parliamentary group.

During the European election, Corriente Roja, led by Ángeles Maestro, left the coalition due to strong disagreements with the leadership's policy, which it described as reformist. The PRT-IR did likewise. A month later, IU's Basque federation approved new statutes that included a change of name to Ezker Batua-Berdeak (EB-B), and under which the organization became a party independent of the federal leadership, associating with United Left through a protocol signed by Gaspar Llamazares. The PCE-EPK opposed this decision.^[46]

In December of 2004 the 8th Federal Assembly of United Left was held on an extraordinary basis, after the crisis opened by the coalition's successive electoral defeats and by division in its leadership. This assembly re-elected Gaspar Llamazares as federal coordinator, against his main opponent, Enrique Santiago, in a highly controversial process that some sectors described as irregular because Santiago's candidacy – backed by the PCE and the Communist Youth – and the list presented by Sebastián Martín Recio – backed by IU's most left-wing sectors – together totaled more than 50% against 49% for Llamazares' official list. Membership was 70,000.^[47]

Gaspar Llamazares' re-election, in January 2005, was highly controversial because it resulted from a system approved in a reform of the statutes prior to the election and during the same Assembly, consisting of having not only half of the new Federal Political Council vote (the body that had until then been competent to elect the federal coordinator), but also the coordinators of the federations. In this way, he secured 54% support, which his opponents also rejected, as a minimum of 60% was required to stand for a second re-election as coordinator, as provided in the statutes. The Guarantees Commission resolved the issue in Llamazares' favor, understanding that the second term had not been exhausted because the 8th Assembly had been brought forward.

During the 8th Legislature United Left was one of the formations that supported the government of José Luis Rodríguez Zapatero in Parliament.

In early 2005 it campaigned for a "no" vote in the referendum on the European Constitution.

The following year it updated its logo, changing it to a red one framed in a square leaning left. This new logo, besides being a nod to its ideological spectrum, also sought to reduce costs by allowing propaganda to be printed in a single ink and to adapt better to any use.^[22]

On 25 January 2007, the federal leadership and the regional leadership of the Community of Madrid signed a "political agreement" under which Inés Sabanés would be the candidate for the presidency of the Community in the 2007 election and Ángel Pérez candidate for the city council, which drew criticism from IU's Political Council in the city of Madrid, which had chosen other candidates in an assembly process among the capital's militants.^[48]

In the 2007 municipal elections it ran alone in eight autonomous communities, and in coalition in the other nine as well as the two autonomous cities: in Asturias with Bloc for Asturias and Los Verdes de Asturias; in Cantabria with Bloque Regeneración; in the Basque Country with Aralar; in Catalonia with Initiative for Catalonia Greens; in Ceuta with the Unión Demócrata Ceutí; in the Valencian Community with the Valencian Nationalist Bloc, Los Verdes, and Republican Left; in the Balearic Islands with the Partit Socialista de Mallorca-Entesa Nacionalista, Los Verdes, and Esquerra Republicana de Catalunya; in Castile and León and in the Region of Murcia with Los Verdes; in Extremadura with Socialistas Independientes de Extremadura; and in Melilla with Coalition for Melilla.

In June 2008 the integration of Coalition for Melilla into the structure of United Left was carried out, becoming a full federation of IU in the autonomous city.^[49]

It lost 256,740 votes compared with the previous local election of 2003.

At the end of 2007, the PCE pushed in IU's Federal Political Council for primary elections to be held to designate the candidate for the presidency of the government in the 2008 general election. Against Gaspar Llamazares, the secretary general of the Partit Comunista del País Valencià, Marga Sanz, ran. The referendum was held in November by a certified-mail system, harshly criticized by the PCE. Finally, with turnout around 38%, Llamazares obtained 13,626 votes (62.5%) and Sanz 8,169 (37.5%).

On 17 November an assembly of IU's Valencian federation was held, in which a new leadership would be elected, taking place amid a deep crisis with the internal current Esquerra i País, already constituted as a party under the name Iniciativa del Poble Valencià (IdPV) and supported by ICV. Some IdPV members had then stopped paying dues as a protest measure against the regional leadership, and IU's federal leadership sent a letter warning that the assembly would be annulled if the regional leadership did not allow them to participate.^[50] The assembly went ahead and Antonio Montalbán was chosen as head of the list, with the support of the PCPV, independents, and Espai Alternatiu.

IdPV challenged the Assembly, and although the petition was unanimously dismissed by the internal oversight body (the Sindicatura de Greuges d'EUPV), the federal leadership decreed primaries within EUPV by postal vote. In the primaries promoted by IU's federal leadership only 33.24% of the Valencian membership participated, choosing IdPV's candidate, Isaura Navarro, with 1,057 votes. EUPV's candidates did not participate and the leadership did not recognize those results, because the process had not been promoted in the legitimate regional body and in any case there had been no quorum (only 30 of the 87 members were present). Thus, in another referendum organized on 11 January 2008 by EUPV's Consell Nacional, Montalbán won with 1,299 votes.^[51] In January 2008, after EUPV's court request to suspend the primaries, the federal leadership recognized the results.^[52]

After the worst results in its history in the 2008 general election, in which United Left obtained only two MPs (won within the coalition with ICV), losing an MP in Madrid, another in Barcelona and the only one in Valencia, Gaspar Llamazares announced his intention to leave his post as general coordinator at the next assembly. In the Congress of Deputies, IU formed the Grupo Parlamentario de Esquerra Republicana-Izquierda Unida-Iniciativa per Catalunya Verds together with ERC and ICV, after the loan of two MPs from the Galician Nationalist Bloc (BNG). On 22 April 2008, former general coordinator Julio Anguita sent the PCE's Federal Committee a document defending the need for a "refoundation" of IU. In his letter, he attributed the electoral debacle to a "lack of a clear line" and to the absence of a coherent program. He defended radical democracy, the struggle for the Third Republic and federalism, both for the coalition's organizational model and for the state. In his view, the debate should be opened at IU's next federal assembly.^[53][54] In July 2008 IU had 48,318 members.^[47]

On 15 and 16 November 2008 the 9th Federal Assembly was held in Rivas-Vaciamadrid, under the slogan Answers from the left (Respuestas por la izquierda). IU's federal presidency lowered to 5% the number of endorsements required to present candidacies, of which there were ultimately five:

That of Cayo Lara, general coordinator of IU in Castile-La Mancha and consensus candidate of the PCE for the list Otra IU es Posible ("Another IU is possible"), which obtained 43% of the vote. That of Inés Sabanés, of the "Llamazarista" current known as IU Abierta, which obtained 27% support. That of senator Joan Josep Nuet, candidate of the Nacional-II or "third way", articulated around Catalan, Madrid, and Aragonese leaders, which in the previous assembly had supported Gaspar Llamazares, obtained 19% of the vote. That of Haizea Miguela, of Ezker Batua, supported by critical sectors of the Basque and Murcian Communist Party of Spain as well as an Extremaduran majority, which obtained 6% support.^[55] That of Juan Manuel Sánchez Gordillo, leader of CUT-BAI, also backed by Convocatoria por Andalucía, which received 5% support among those present.^[56]

The assembly concluded without choosing a new Federal Coordinator to replace Gaspar Llamazares, due to disagreement among the coalition's different currents. A commission, chaired by the most-voted candidate, Cayo Lara, was tasked with preparing the call for the full Political Council (at the assembly only half is elected, 90 members; the other 90 are elected by territorial federations).^[57]

Finally, the Federal Political Council, convened on 14 December, elected Cayo Lara as the coalition's federal coordinator with 55.08% of the vote, against the Nacional II candidate Joan Josep Nuet. IU Abierta had designated Eberhard Grosske as its candidate,^[58] but ultimately preferred to withdraw him and abstain.^[59]

On the other hand, on 22 November,^[60] Espacio Alternativo approved a resolution by which it definitively abandoned its integration in United Left,^[61] organizing itself as a political party with the intention of running in the 2009 European election under the name Izquierda Anticapitalista, although most of its militants in the Valencian Community continued participating within EUPV, notably the economist Manolo Colomer and EUPV's social-movements lead Antonio Arnau.

Cayo Lara, despite representing the PCE within IU, integrated from the outset people from all sectors and currents of the organization into IU's new leadership. In his first public intervention, Lara mentioned the poor, the unemployed and mortgage holders, and called for a general strike which he considered necessary, urging IU to abandon internal struggles and to focus on what was really happening in the country.^[62]

Lara emphasized from the first moment the commitment to distance IU from the PSOE, considering that it defends neoliberalism just like the People's Party, and to refound the anti-capitalist left in order to converge with other left-wing forces, take to the streets and present an alternative to the crisis. The new party leadership demanded that both PP and PSOE fully comply with the content of the Spanish Constitution of 1978, understanding that rights to equality and work, among others, had not been fulfilled.

In March 2009 Javier Madrazo resigned as general coordinator of Ezker Batua as a consequence of the poor result obtained in the 2009 election, and was replaced by Mikel Arana. In April, the internal current headed by Oskar Matute split from EB to create Alternatiba, a party that later joined the coalitions Bildu, Amaiur, and EH Bildu.

In the 2009 European election IU repeated its coalition with ICV, called La Izquierda ("The Left"), which, although it fell slightly in support, stabilized the decline by obtaining practically the same backing as in the previous election: 3.71% of the vote. Although IU-ICV had agreed to integrate into the same European political group, ICV broke the pact and joined the Greens/EFA group, so IU decided on 27 June 2009 not to renew it on the same terms.^[63]

In November 2009 the state attorney general Cándido Conde-Pumpido revealed that there were 730 open cases for alleged corruption against public officials from political parties, with 20 of them (2.7%) corresponding to United Left.^[64][65]

On 28 November 2009 IU approved a project of "Refoundation of the Left", which sought not only to refound IU but the refoundation of the entire left into a "stronger, anti-capitalist, transformative and republican political force", calling on all sectors of the alternative left in a process of "accumulation of forces".^[66][67] The refoundation sought convergence with the extra-parliamentary left and even with left-wing sectors disenchanted with the PSOE.^[68]

But this process was not carried out in all federations and was implemented unevenly, as in the case of IU's Asturian federation, IU-Asturias – a stronghold of Izquierda Abierta which kept the Communist Party of Asturias expelled and did not participate in the 1st Refoundation Assembly.^[69] For its part, IU's Madrid federation leadership (IUCM) had chosen the electoral candidacies proposed by Ángel Pérez a month before that assembly,^[70] provoking harsh criticism. That same year the regional MPs in the Assembly of Madrid Inés Sabanés^[71] and Reyes Montiel^[72] left for Equo.

On 24 September 2010 United Left also reached an agreement with The Greens–Green Group, calling on both organizations to advance in processes of political and social convergence. The agreement included forming a "working table" (Mesa de Trabajo) to develop a New Political Program, meant to overcome capitalism, with which the whole of left-wing political organizations and ecological, feminist, and pacifist organizations would feel represented.^[73] This agreement broke down shortly thereafter and ended up in court for breach of the agreed and signed accords.^[74]

The first federation to complete the first phase of refoundation was Izquierda Unida de las Islas Baleares (EUIB), which temporarily constituted itself as Esquerra Alternativa i Verda,^[75] and later returned to its original name. In Galicia, events were organized in several regions, including one in Santiago de Compostela attended by representatives of the Real Academia Galega and forces such as Workers' Commissions (CC.OO.), the Galician People's Front, the Central Unitaria de Traballadores, and the Marcha Mundial das Mulleres.^[76]

On 26 June 2010 the 1st Federal Assembly was held, marking the beginning of the nationwide refoundation process, in which social organizations of all kinds participated: unions from different professional sectors, neighborhood associations, pro-LGBT rights groups, and even the Foro por la Memoria. Observers included Batzarre, Zutik, CC.OO., UGT, ICV, Foro Mundial de Alternativas, and the Foro por la Memoria. At that assembly the support of Republican Left (an organization that ultimately rejoined the coalition^[77]) for the Refundación de la Izquierda process was made public.^[78]

One of the fundamental agreements of this refoundation process was the creation of a mechanism to verify membership rolls in the Federal Executive Commission, which was launched in September 2009. With the updating of the rolls it was verified that the number of members was lower than had been believed.^[79]

As a result of this process, alliances were established such as that between Batzarre and Izquierda Unida de Navarra (IUN), which on 29 January 2011 presented the electoral brand Izquierda-Ezkerra,^[80] which, after a consultation of both organizations' membership, decided to run in municipal and regional elections to generate an open left-wing political movement that would bet on inter-identity unity of the Navarrese lefts,^[81] with an electoral program elaborated in a participatory manner.^[82]

Republican Left also rejoined IU after nine years of rupture between the two organizations.

On 4 July 2011 IU announced at a press conference the "Social Convocation" process (Convocatoria Social), an invitation to the public to participate in drafting a program through the convening of open assemblies, as well as the intention to hold a series of meetings with other left-wing political forces in order to run in the next general election.^[83]

As a result of these meetings, IU ran in the general election in Navarre in the Izquierda-Ezkerra coalition,^[84] in Aragón with the Chunta Aragonesista (CHA),^[85] in Catalonia with ICV, in Extremadura with SIEX, in Ceuta with the Partido Democrático y Social de Ceuta,^[86] in the Canary Islands with Iniciativa por El Hierro (IpH), Canarias por la Izquierda (CxI) and the Partido por los Servicios y de los Empleados Públicos (PSyEP), in Melilla with Coalition for Melilla, and in several other constituencies with green parties such as Els Verds del País Valencià (EVPV), Gira Madrid-Los Verdes (GM-LV), Els Verds–Opció Verda (EV-OP), Los Verdes de Asturias, Iniciativa Verds, and Ecosocialistas de la Región de Murcia.^[87][88] In the case of the Basque Country, IU broke with Ezker Batua amid an internal crisis, and Ezker Anitza was formed as the new Basque federation, supported by regional coordinator Mikel Arana and the PCE-EPK.

In addition, for the Senate it expanded the alliance in Murcia with Equo and Movimiento por Santomera^[89] and in Catalonia with Catalan Agreement of Progress.^[90]

Finally, it ran in the 2011 general election for the Congress of Deputies, with Cayo Lara as head of the list,^[91] together with twelve other political forces under the name Plural Left,^[92] obtaining 1,680,810 votes (6.92% of valid votes), rising to eleven MPs (two from ICV and one from CHA, plus one from EUiA) and recovering its Parliamentary group; the best result since 1996 under Julio Anguita.^[93] CHA MP Chesús Yuste held the seat for 31 months of the legislature, later passing it to IU Aragon's Álvaro Sanz for the remaining months, as provided in the agreement under which they ran.

According to the Court of Auditors, in 2011 IU was one of seventeen parties in technical bankruptcy, that is, with negative net worth, specifically 8,520,508 euros.^[94]

In 2012 elections were held in Asturias and Andalusia, Galicia and Catalonia, in which IU increased its representation. In Andalusia, IULV-CA doubled its MPs compared with 2008, from six to twelve, obtaining 437,445 votes (11.34%) and holding the balance of power; in Asturias it was the only force represented in the parliament that grew compared with the previous year's election, reaching 68,827 votes and one additional seat, ultimately holding five regional MPs;^[95] in Galicia IU's Galician federation, Esquerda Unida, ran within the Galician Left Alternative coalition together with Renewal–Nationalist Brotherhood, Equo, and Espazo Ecosocialista Galego, with that electoral grouping surpassing the Galician Nationalist Bloc (BNG), obtaining 13.99% and nine seats; and in Catalonia ICV-EUiA obtained 13 seats (three for EUiA) and 9.89% of the final count, positioning itself as the fifth electoral force.

In Madrid, although in the previous regional and municipal elections, according to The Greens–Green Group, about one hundred of its members had been elected as councillors, some of them in coalition with IU,^[96] on 26 April 2012 its president Esteban Cabal declared the coalition broken, claiming IUCM had breached the agreements, accusing them of behaving like "criminals", while Gira Madrid-Los Verdes, which did not win any councillor, maintained its agreement.^[97]

At the end of 2012 IU held its 10th Assembly, in which Cayo Lara was re-elected coordinator unanimously and the Federal Political Council was renewed with social-movement activists and trade unionists, as well as representatives of all the organization's currents.^[98] In 2013 the organization had 36,000 members.^[99]

In 2013 Coalition for Melilla, after five years forming IU's federation in the autonomous city, decided to detach itself, so from then on United Left formed its own federation there.^[100]

In April 2014 the Sevillian businessman José Antonio González stated before judge Mercedes Alaya that he had delivered 70,000 euros to an IU official as an alleged quid pro quo for awarded contracts.^[101] The organization considered the claim lacking in rigor and requested that, before giving it credence, the allegedly involved person be identified.^[102]

Ahead of the 2014 European election United Left again chose Willy Meyer as head of the list for the third time, despite internal voices calling for renewal of candidates and selection methods.^[103][104] Although the La Izquierda Plural list in which IU participated was the third political force with 1,575,308 votes (10.03%) and six seats (out of 54), a gain of four seats compared with the previous European election,^[105] Podemos, a recently created left-wing party that drew up its lists through open primaries, was the fourth most voted (7.98%), obtaining five seats.^[106] For several media, Podemos was "the surprise" of the election and a warning to IU, which had not managed to capitalize on existing social discontent.^{[107][108][109]} Podemos surpassed IU in five autonomous communities, including the Community of Madrid.^[110]

On 25 June 2014 Willy Meyer announced his resignation, without having taken up his seat, after it became public that the pension fund for MEPs in which he participated was managed by a SICAV in Luxembourg,^[111] and he was replaced by the next person on the list, Javier Couso.

In January 2015 IU organized for the first time in its history open primaries for supporters, to choose IU's next candidate for the Congress of Deputies. Of the 82,177 on the roll, 47,082 were supporters (more than 57%) and 35,095 were dues-paying militants.^[112] Finally Alberto Garzón was elected as the candidate, the only candidate able to obtain enough endorsements to stand.^[113]

In February 2015 a crisis erupted in IU's Madrid federation (IUCM), following the regional leadership's refusal to demand political accountability over the Bankia "black cards" case (Caja Madrid), which led IU's newly chosen candidate for president of the Community of Madrid, Tania Sánchez, to leave, along with a group of around 60 militants^[114] who founded a new party called Convocatoria por Madrid.^[115]

The rest of the Madrid federation's critical sector did not leave IU, although several local assemblies, the Partido Comunista de Madrid (PCM) and the Union of Communist Youth of Spain (UJCE) broke with the regional leadership and referenced only IU at the federal level.^[116][117] After IUCM's leadership informed Ahora Madrid of its intention to run its own list in the municipal election,^[118] following a referendum disavowed by IU's federal leadership,^[119] Mauricio Valiente was forced to choose between IUCM membership and running in Ahora Madrid's primaries; he chose to request a formal certificate of resignation from IU federal, claiming IUCM had expelled him, and ran in Ahora Madrid's primaries after consulting assemblies.^[120]

Also in February, the Unitarian Candidacy of Workers (CUT), a political party affiliated with IU since its foundation in 1986, definitively left due to disagreement with the "pacts policy" that, in its view, IU's Andalusian federation was carrying out with the PSOE.^[121] This meant that from that moment on, militants of that party could continue to appear on IU lists, but could also seek alliances with other political formations.

In the 2015 municipal and regional elections, IU suffered a sharp decline in regional parliaments, obtaining only fourteen MPs (five in Andalusia, one in Aragón, five in Asturias, one in Castile and León, and two in Navarre). However, at the municipal level it increased by adding councillors obtained under its own initials to those obtained in unitary "popular unity" lists, some of which won mayoralties in Spanish provincial capitals and other cities.^[122]

Considering that "popular unity" candidacies were "the only path" to win the December 2015 general election, IU's candidate for prime minister, Alberto Garzón, proposed that his organization support this option; 91% of IU's leadership supported the initiative on 5 June, opening a round of contacts with leaders of other left-wing parties.^[123] A few days later, on 14 June, the federal leadership severed ties with IUCM, whose leadership had breached federal agreements on accountability in the Bankia case and on convergence with other political forces, announcing the creation of a new IU federation in the Community of Madrid, organized in territorial and district base assemblies, supervised by the federal leadership.^[124]

In July 2015 the citizen platform Ahora en Común was launched, aiming to create a candidacy for the December 2015 general election in which all left-wing parties, social organizations and independent people would converge. At that time, officeholders from Podemos, IU, Equo and municipalist candidacies joined.^[125] In September IU approved joining this initiative, hoping it would serve as a meeting space among all political forces.^[126] Podemos' leadership refused to join and only favored agreements in some autonomous communities.^[127]

Finally, the three promoters of the initiative announced their departure from Ahora en Común, taking with them the "Ahora en Común" brand they had registered both with the Ministry of the Interior and the Patents and Trademarks Office, since Podemos had not joined and because they considered the platform had become a space for disputes among political parties.^[128] After the announcement of nationwide primaries in Ahora en Común, Equo left the platform, considering that the primaries did not help convergence with Podemos.^[129] Those who remained continued under the name Unidad Popular en Común,^[130] and the coalition that appeared on ballots as "Unidad Popular: Izquierda Unida, Unidad Popular en Común (IU-UPeC)" was also constituted,^[131] formed by IU and Unidad Popular en Común itself, plus Chunta Aragonesista, Izquierda Asturiana, Batzarre-Asamblea de Izquierdas, Construyendo la Izquierda-Alternativa Socialista, Segoviemos, and Izquierda Castellana.

In October open primaries were held to choose Popular Unity's candidates, using the Dowdall method of proportional selection previously used in Ahora Madrid, with list positions ordered by gender-parity criteria.^[132] Alberto Garzón won the primaries for prime-ministerial candidate with 23,712 (96%) out of a total of 24,615, having run against thirteen other candidates.^[133]

In Galicia IU integrated into the En Marea coalition, together with the municipalist "Mareas", Anova and Podemos, agreeing that MPs elected under that candidacy would form their own parliamentary group independent of the state-level formations.^[134] Similarly, in Catalonia IU's reference EUiA integrated into the En Comú Podem coalition, together with Barcelona en Comú, ICV, and Podem, also agreeing that its MPs would integrate their own parliamentary group.^[135] In addition, in Navarre, the Izquierda-Ezkerra formation (in which IU and Batzarre are integrated) supported the Cambio-Aldaketa candidacy for the Senate, together with Geroa Bai, EH Bildu, and Podemos.^[136]

In the December 2015 general election the Popular Unity electoral coalition collapsed in votes and won only two MPs in the Madrid constituency.^[137] These poor results are explained, besides by the weak relationship between votes and seats in Spain's electoral system, by the enormous rise of Podemos.^[138]

On 20 April 2016 some media reported that Podemos and Popular Unity (IU-UP) were negotiating to present a joint list, in view of possible new general elections in June.^[139][140] That same month, more than a hundred intellectuals and artists such as El Gran Wyoming, Antonia San Juan, Carlos Bardem, Fernando Tejero, and Luis Tosar signed a manifesto calling on Podemos, IU, the existing territorial "confluences" and other formations to group together and "join forces" for the next elections.^[141] Toward 30 April, both parties stated that formal talks had begun for a possible coalition.^[142]

Initially IU submitted the possible agreement with Podemos to a consultation of its base, through a vote held between 2 and 4 May.^[143] The results were 84.5% in favor of the agreement.^[144] Negotiations also began on a joint minimal program, although IU and Podemos opted to keep their maximal programs intact.^[145][146] On 9 May, Pablo Iglesias and Alberto Garzón officially announced that a pre-agreement had been reached to present a joint list of candidates in the next general election. The pact guaranteed that one sixth of the candidates obtained by the coalition (according to forecasts and not counting regional coalitions such as En Comú Podem, En Marea, and És el moment) would belong to IU candidates; it also preserved each party's identifying features.^[147] Podemos and IU held separate consultations of their bases on 10 and 11 May to confirm convergence,^[148] with IU's consultation achieving higher participation and more supporting votes among the 22,321 militants and 49,720 supporters called to vote.^[149][150]

The statewide Unidos Podemos candidacy in which Podemos and Equo also participated had different additional supports in some constituencies:

Andalusia: Candidatura Unitaria de Trabajadores.

Aragón: Ahora Alto Aragón en Común and Puyalón.

Castile and León: Construyendo la Izquierda-Alternativa Socialista, Izquierda Castellana, and Segoviemos.

Ceuta: Caballas Coalition (the Ceutan Democratic Union (UDCE) and the Socialist Party of the People of Ceuta (PSPC)).

Community of Madrid: Construyendo la Izquierda-Alternativa Socialista and For a Fairer World.

Chartered Community of Navarre: Batzarre.

Balearic Islands: Més per les Illes Balear.

Asturias: Construyendo la Izquierda-Alternativa Socialista, Izquierda Asturiana.

IU's Galician federation, Esquerda Unida, integrated into the En Marea coalition together with Anova-Irmandade Nacionalista and Podemos Galicia, while the Valencian federation integrated into Compromís-Podemos-EUPV: A la Valenciana together with Compromís and Podem Comunitat Valenciana.

For its part, United and Alternative Left, IU's reference in Catalonia, integrated into the En Comú Podem-Guanyem el Canvi coalition, together with Podemos Catalunya, ICV, Equo, and Barcelona en Comú.

On 26 and 27 May online and on 29 May in person at branch offices, IU's membership elected the new leadership ahead of the 11th Federal Assembly, for the first time through primaries, with 40.2% participation of the membership roll. Alberto Garzón's list was chosen with 74.7% of the vote, against MEP Paloma López Bermejo, backed by Cayo Lara, who obtained 20.8%, while Tasio Oliver, backed by Gaspar Llamazares and Izquierda Abierta, achieved 4.6%.

On 3 and 4 June the 11th Federal Assembly of IU was held, in which Alberto Garzón was officially elected as the new general coordinator. The vote results gave Garzón's team, made up of a new generation of leaders, enough weight to decide the organization's future.^[151][152]

On 8 June 2019 United Left approved temporarily suspending the protocol with United and Alternative Left, after learning that EUiA members had launched a political project called Sobiranistes. It also agreed to call an open assembly in Catalonia to explain this decision to EUiA militants who support IU's alliance policy and program; the assembly was eventually held on 3 July 2019 in Sant Adrià de Besòs (Barcelona) and attended by Alberto Garzón. This call has been seen as a first step toward creating an IU Catalan federation that would be called United Left Catalonia, although it states as its objective to "recover EUiA".^[153]

On 4 December 2019 the Feminist Party of Spain issued a statement criticizing the presentation of laws and proposals by Podemos, a party integrated into the Unidas Podemos coalition, of which IU was part.^[154] The statement generated much controversy, to the point that IU's LGBT area (ALEAS-IU) called for the party's expulsion from the coalition.^[155] Finally, on 22 February 2020 IU's Political and Social Assembly approved the expulsion of the Feminist Party for repeated breaches of statutes and for maintaining positions contrary to those approved in IU's bodies, ending five years of the party's integration into the coalition since joining in 2015.^[156][157]

In the April 2019 general election United Left renewed its agreement with Podemos in the Unidas Podemos coalition.^[158] In the November 2019 general election the party, within Unidas Podemos, won six MPs. The electoral coalition made a pact with the acting prime minister, Pedro Sánchez (PSOE), establishing a coalition government between Unidas Podemos and the PSOE.^[159] In this way Unidas Podemos obtained five of the 22 ministries in the Second Sánchez government. Of those five, one went to Alberto Garzón: the Ministry of Consumer Affairs.^[160][161] It was the first time in IU's history that it formed part of the Government of Spain and the first time since 1939 that a member of the Communist Party of Spain did so.^[162]

In the 23 July 2023 general election United Left did not renew the Unidas Podemos coalition and instead became one of the founding members of the Sumar electoral coalition, led by Yolanda Díaz.^[163] In that election Sumar won 31 MP seats in the Congress of Deputies, of whom five belonged to United Left.^[164] After Alberto Garzón's departure, the Ministry of Consumer Affairs was abolished, with its functions transferred to the Ministry of Social Rights, Consumer Affairs and Agenda 2030;^[165] IU continued in the Council of Ministers with the same presence as in the previous legislature, this time with the Ministry of Youth and Children, headed by Sira Rego.^[166]

After Garzón's departure the party convened the 13th Federal Assembly to choose a new coordinator in May 2024. The list headed by Antonio Maillo obtained 53.4% of the membership vote, surpassing minister Sira Rego:^[167][168] Antonio Maillo became United Left's sixth general coordinator. The candidacies were as follows:^[168]

Antonio Maillo (53.4% of total votes), backed by the PCE leadership and the federations of Asturias and Andalusia

Sira Rego (23.4%), then Minister of Education

Álvaro Aguilera (14.1%), then coordinator of Izquierda Unida de Madrid

José Antonio García Rubio (8.3%), of the La Izquierda Necesaria current.

In June 2024, in the European election, United Left, integrated into the Sumar coalition, was left out of the European Parliament for the first time in its history. Maillo was critical of Sumar and called for a change in its structure.^[169] Shortly after the Errejón case scandal, which further weakened Sumar, United Left initiated in November 2024 a process called Convocatoria por la Democracia ("Convocation for Democracy"). This process aims to recompose the left as a replacement for Sumar.^[170]

Party		Notes
	Communist Party of Spain (PCE)
	La Aurora Marxist Organization (La Aurora (OM))	Not a political party. Joined in 1998
	Republican Left (IR)	Left in 2002, rejoined in 2011
	Unitarian Candidacy of Workers (CUT)	Left in 2015, rejoined in 2018
Former members
	Feminist Party of Spain (PFE)	Joined in October 2015, expelled in February 2020 due to its stances on transgender rights.
	Humanist Party (PH)	April–July 1986
	Carlist Party (PC)	Expelled in 1987
	Progressive Federation (FP)	Left in December 1987, due to being dissolved.
	Communist Party of the Peoples of Spain (PCPE)	Left in 1988
	Socialist Action Party (PASOC)	Dissolved in 2001.
	Red Current (CR)	Joined in 2002, left in 2004
	Anti-capitalists (IA)	Joined in 1995, left in 2008
	Coalition for Melilla (CpM)	Joined in 2008, left in 2013
	Open Left (IzAb)	Joined in 2012, dissolved in 2018.

In 1986, the PCE promoted United Left (IU) and participated with other political forces in its foundation, first constituted as an electoral coalition and later as a federation of parties. At the 13th Congress of the PCE it was decided to transfer its sovereignty to the bodies of IU, with its secretary-general Gerardo Iglesias also becoming the first general coordinator of the new coalition.

Under the leadership of the then secretary-general of the PCE, Julio Anguita, IU achieved the best results in its history, but health problems forced him to step down from the leadership. In 2008, the PCE regained leadership of the coalition with the election of Cayo Lara as general coordinator, with the objective of the Refoundation of the Left.

It was part of United Left (IU) from its creation in 1986, participating actively in the coalition until 2002, when it broke away due to disagreements with the leadership of Gaspar Llamazares.

On 19 June 2010, part of its membership decided to participate in the process of Refoundation of the Left promoted by the new leadership of Cayo Lara, and on 6 February 2011, the party's return to United Left and the participation of its members in the coalition lists was confirmed,^[77] although the sector opposed to this integration split off to create Republican Alternative.^[171]

At the 3rd IU Assembly in March 1992, the Communist Youth Union of Spain (UJCE), the youth organization of the PCE, was recognized as a political organization affiliated with IU, independent from the PCE. At that assembly it opposed the idea of constituting IU as a conventional political party, defending the theses of the PCE leadership, headed by Julio Anguita, of moving from the phase of coalition to that of a political and social movement.

At the 9th Federal Assembly of IU they supported the list headed by Cayo Lara, which won a majority, and he was elected coordinator. In this way the process of Refoundation of the Left began and four UJCE members became part of IU's federal political council.

La Aurora Marxist Organization was founded in 1974 as the Revolutionary Workers' Party of Spain (PORE) and joined United Left in 1998. In 2005 it created the Redes current within IU.^[172] Its section in Catalonia, the most active, is integrated into EUiA through the Bastida current, while in the Basque Country it was integrated into Ezker Batua-Berdeak through Sarea/Redes (although part of the POR left the coalition in 2011 to call for a vote for Amaiur through the Erabaki collective).^[173] In 2013 it changed its name to that of its publication, La Aurora.

On 15 November 2010, the Regional Political Council of IU in Murcia unanimously approved the incorporation of a new political organization, Ecosocialists of the Region of Murcia, made up of people outside the left-wing coalition and independent members of it, and established with the objective, according to its statutes, of working in coordination with United Left to "transform society on the basis of the principles of social ecology, participatory democracy, and socialism".^[174]

On 23 December 2010, United Left met in El Hierro with representatives of the leadership of Initiative for El Hierro, where the political agreement reached by both political formations was finalized. The agreement, ratified by the general assembly of Initiative for El Hierro, meant the recognition of this political force as the sole reference of United Left in El Hierro, maintaining its own political identity and decision-making capacity. Both sides maintain that the agreement reached aims to go beyond a simple electoral alliance and enable the process of reorganization of the entire transformative and alternative Canarian left.^[175]

Broad Front was constituted in 2013 as an internal current of IUCM,^[176] but in 2015 they announced their constitution as a political party within IU.^[177] After the defederation of IUCM, Broad Front of Madrid joined as a constituent party of the new Madrid federation of IU.

Name	Period
Gerardo Iglesias	1986–1989
Julio Anguita	1989–1999
Francisco Frutos	1999–2001
Gaspar Llamazares	2001–2008
Cayo Lara	2008–2016
Alberto Garzón	2016–2023
Antonio Maíllo	2024–present

• Andalusia: Izquierda Unida Los Verdes - Convocatoría por Andalucía (United Left/The Greens - Assembly for Andalusia)
• Aragon: Izquierda Unida Aragón (United Left of Aragon)
• Asturias: Izquierda Xunida de Asturies (United Left of Asturias)
• Balearic Islands: Esquerra Unida de les Illes Balears (United Left of the Balearic Islands)
• Canary Islands: Izquierda Unida Canaria (Canarian United Left)
• Cantabria: Izquierda Unida de Cantabria (Cantabrian United Left)
• Castilla–La Mancha: Izquierda Unida de Castilla-La Mancha (United Left of Castilla–La Mancha)
• Catalonia: Esquerra Unida Catalunya (United Left Catalonia, Founded in July 2019; suspended in June 2019 United and Alternative Left)^[178]
• Castilla y León: Izquierda Unida de Castilla y León (United Left of Castile and León)
• Ceuta: Izquierda Unida de Ceuta (United Left of Ceuta)
• Euskadi: Izquierda Unida - Los Verdes: Ezker Anitza (United Left - The Greens: Plural Left)
• Extremadura: Izquierda Unida Extremadura (United Left Extremadura)
• Galicia: Esquerda Unida (United Left of Galicia)
• La Rioja: Izquierda Unida La Rioja (United Left-La Rioja)
• Madrid: Izquierda Unida-Madrid (United Left-Madrid).^[179] Izquierda Unida de la Comunidad de Madrid (United Left of the Community of Madrid) was expelled in 2015. The new federation, IU-M, was created in 2016.^[180]
• Melilla: Izquierda Unida - Federación de Melilla (United Left - Melilla Federation)
• Murcia: Izquierda Unida-Verdes de la Región de Murcia (United Left - Greens of the Region of Murcia)
• Navarra: Izquierda Unida de Navarra - Nafarroako Ezker Batua (United Left of Navarra)
• Valencian Community: Esquerra Unida del País Valencià (United Left of the Valencian Country)

Cortes Generales
Election	Leading candidate	Congress					Senate		Gov.
		Votes	%	#	Seats	+/–	Seats	+/–
1986	Gerardo Iglesias	935,504	4.6	5th	7 / 350	3	0 / 208	0	Opposition
1989	Julio Anguita	1,858,588	9.1	3rd	17 / 350	10	1 / 208	1	Opposition
1993		2,253,722	9.6	3rd	18 / 350	1	0 / 208	1	Opposition
1996		2,639,774	10.5	3rd	21 / 350	3	0 / 208	0	Opposition
2000	Francisco Frutos	1,263,043	5.4	4th	8 / 350	13	0 / 208	0	Opposition
2004	Gaspar Llamazares	1,284,081	5.0	6th	5 / 350	3	1 / 208	1	Confidence and supply
2008		969,946	3.8	6th	2 / 350	3	1 / 208	0	Opposition
2011	Cayo Lara	with Plural Left			7 / 350	5	0 / 208	1	Opposition
2015		with Popular Unity			2 / 350	5	0 / 208	0	New election
2016	Alberto Garzón[a]	with Unidos Podemos			8 / 350	6	2 / 208	2	Opposition (2016–18)
									Confidence and supply (2018–19)
Apr-2019		with Unidas Podemos			5 / 350	3	0 / 208	2	New election
Nov-2019		with Unidas Podemos			5 / 350	0	0 / 208	0	Coalition (PSOE–UP)
2023	Alberto Garzón[b]	with Sumar			5 / 350	0	0 / 208	0	Coalition (PSOE–Sumar)

European Parliament
Election	Leading candidate	Votes	%	#	Seats	+/–	EP Group
1987	Fernando Pérez Royo	1,011,830	5.3	4th	3 / 60	—	COM
1989		961,742	6.1	4th	4 / 60	1	COM (EUL)
1994	Alonso Puerta	2,497,671	13.4	3rd	9 / 64	5	EUL
1999		1,221,566	5.8	3rd	4 / 64	5	GUE/NGL
2004	Willy Meyer	643,136	4.1	4th	2 / 54	2
2009		with The Left			2 / 54	0
2014		with Plural Left			4 / 54	2
2019	Sira Rego[c]	with UPCE			2 / 59	2
2024	Manu Pineda[d]	with Sumar			0 / 61	2	—

• Official website
• Izquierda Unida Los Verdes – Convocatoría por Andalucía
• Izquierda Unida Aragón
• Izquierda Xunida d'Asturies
• Izquierda Unida de Cantabria
• Izquierda Unida – Izquierda de Castilla-La Mancha
• Esquerda Unida-Izquierda Unida
• Esquerra Unida de les Illes Balears
• Izquierda Unida – La Rioja
• Izquierda Unida de la Comunidad de Madrid
• Izquierda Unida de Navarra – Nafarroako Ezker Batua
• Esquerra Unida del País Valencià