United Left

A Spanish federation of left-wing parties defined in its statutes as socialist, republican, federal, feminist, and environmentalist. It emerged as an electoral coalition formed to contest the 1986 Spanish general election, bringing together various left-wing parties under the leadership of the Communist Party of Spain. In November 1992, it registered with the Ministry of the Interior as a federation of parties. Since 2024, its general coordinator has been Antonio Maíllo.

It has a strong territorial presence (at both municipal and regional levels), particularly in Andalusia and Asturias. Historically, the federation has been disadvantaged by the Spanish electoral system, generally achieving low results in elections to the Congress of Deputies. For this reason, and due to its pluralistic nature, IU contests elections as part of coalitions. In the general elections of 2016, April 2019, and November 2019, IU was part of the Unidas Podemos electoral coalition alongside Podemos and other political parties. In the 2023 general election, IU participated in the Sumar coalition and secured five out of the 350 parliamentary seats.

IU has been part of the Spanish government since 2020; it held the Ministry of Consumer Affairs during Pedro Sánchez's second government (2020–2023), with Alberto Garzón serving as minister until 2023. Under Pedro Sánchez's third government, it has held the Ministry of Youth and Children since 2023, with Sira Rego serving as minister. It has also participated in the government of Asturias since 2023.

General Coordinator: Gerardo Iglesias (29 April 1986 – 1 November 1989), Julio Anguita (1 November 1989 – 29 October 2000), Gaspar Llamazares (29 October 2000 – 14 December 2008), Cayo Lara (14 December 2008 – 4 June 2016), Alberto Garzón (5 June 2016 – 17 November 2023), Antonio Maíllo (since 19 May 2024)