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.

IU took part in the Unidas Podemos coalition and the corresponding parliamentary group in the Congreso de los Diputados between 2016 and 2023.

[10] With this premise, the PCE began developing closer relations with other left-wing groups, with the vision of forming a broad left coalition.

[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.