Portugal operates a multi-party system of competitive legislatures/local administrative governments at the national-, regional- and local-levels. The Assembly of the Republic, Regional Assemblies and local municipalities and parishes, are dominated by two political parties, the Socialist Party and the Social Democratic Party, in addition to the Unitary Democratic Coalition (Portuguese Communist Party and Ecologist Party "The Greens"), the Left Bloc and the Democratic and Social Centre – People's Party, which garner between 5 and 15% of the vote regularly.

What two political parties dominate Portugal's government?