The PTE was formed around 1967, following a split from the 'Unidad' group within the Unified Socialist Party of Catalonia (PSUC).

[1] The Catalan group unified with small splinter fractions of the Communist Party of Spain (PCE), especially from Seville.

At the 2nd congress of PCE(i) in 1975 the party changed its name to Party of Labour of Spain (in Spanish: Partido del Trabajo del España, PTE) and adopted an internal federal structure.

The youth wing of PTE was Young Red Guard of Spain (Joven Guardia Roja).

In 1977 PTE formed the Democratic Left Front (FDI) to contest the Spanish general election.