Socialist Party

The Socialist Party (Portuguese: Partido Socialista [pɐɾˈtiðu susiɐˈliʃtɐ], PS) is a social democratic political party in Portugal. It was founded on 19 April 1973 in the German city of Bad Münstereifel by militants who were at the time with the Portuguese Socialist Action (Portuguese: Acção Socialista Portuguesa). The PS is a member of the Socialist International, Progressive Alliance and Party of European Socialists, and has eight members in the European Parliament within the Progressive Alliance of Socialists and Democrats group during the 10th European Parliament.

The party won the 1976 general election and formed the first constitutional government after the 1974 revolution, with Mário Soares as prime minister. However, the government was unstable and fell in 1978. The PS lost the 1979 election, but returned to power in 1983, forming, with the Social Democratic Party, a Central Bloc coalition. It lasted two years and in 1985, the party was defeated and went back to opposition, remaining there for 10 years and losing the two following general elections. Under António Guterres, the party won the 1995 general election and returned to power, lasting until 2002, upon the resignation of Guterres. The party made a comeback and won a historic absolute majority in the 2005 general election under the leadership of José Sócrates. By 2011, the economic crisis led the party to lose the 2011 snap election and the party returned to the opposition. Despite losing the 2015 election, the party formed an agreement with the Left Bloc and the Unitary Democratic Coalition and managed to appoint António Costa as Prime Minister. Costa remained in office for 9 years, until 2024, and during his term won two elections, the last one, in 2022, with an absolute majority. After Costa's resignation, the party narrowly lost the 2024 election, thus, returning to opposition. The party again lost the 2025 election by a larger margin and even fell to third place in Parliament for first time since the 1974 revolution.