Sumar

Sumar is the left-wing electoral Coalition that forms the junior governing partner in Spain's PSOE-Sumar Coalition. Founded in 2023 under the leadership of Yolanda Díaz as a merger of Podemos's successor movements, left-wing independents, and regional left parties, Sumar holds several cabinet ministries including Labour and Social Economy. On housing, Sumar is positioned to PSOE's left: it supported the Plan Estatal de Vivienda 2026-2030 but argued that supply investment without simultaneous rent controls was insufficient to protect existing renters in stressed markets.

When the rent-freeze extension was defeated in Congress on 29 April 2026, Verónica Barbero (Sumar's housing spokesperson) criticised the absence of party discipline among the government's parliamentary allies, identifying Junts and PNV defections as the proximate cause. Sumar's position is that housing legislation should operate on two tracks — supply and price controls — simultaneously, reflecting the party's broader economic programme of market correction through state intervention.

Sumar's electoral support is concentrated in urban areas with acute rental pressure, giving the party a direct constituent interest in the housing outcome; the defeat of the rent freeze is a political liability Sumar has been quick to attribute to parliamentary Coalition fragility rather than its own policy failure.