The Panhellenic Socialist Movement, known mostly by its acronym PASOK, is a social-democratic political party in Greece. Until 2012 it was one of the two major parties in the country, along with New Democracy, its main political rival. In the June 2023 Greek legislative election it once again held firm on to its position of one of the ”big three” political parties of Greece.

New Democracy is a liberal-conservative political party in Greece. In contemporary Greek politics, New Democracy has been the main centre-right to right-wing political party and one of the two major parties along with its historic rival, the Panhellenic Socialist Movement (PASOK). New Democracy and PASOK were created in the wake of the toppling of the military junta in 1974, ruling Greece in succession for the next four decades. Following the electoral decline of PASOK, New Democracy remained one of the two major parties in Greece, the other being the Coalition of the Radical Left (SYRIZA). The party was founded in 1974 by Konstantinos Karamanlis and in the same year it formed the first cabinet of the Third Hellenic Republic. New Democracy is a member of the European People's Party, the largest European political party since 1999, the Centrist Democrat International, and the International Democracy Union.