Workers Party of Socialist Unity (Portuguese: Partido Operário de Unidade Socialista pronounced: [pɐɾˈtiðw ɔpɨˈɾaɾju dj uniˈðaðɨ susjɐˈliʃtɐ] POUS) is a small Trotskyist political party in Portugal founded in 1976 after a split from the Portuguese Socialist Party. It is a member of the Fourth International led by Pierre Lambert.