Singapore is a unitary multiparty parliamentary republic, with a Westminster system of unicameral parliamentary government. The People's Action Party has won every election since self-government in 1959. One of the five founding members of the Association of Southeast Asian Nations (ASEAN), Singapore is also the host of the Asia-Pacific Economic Cooperation (APEC) Secretariat, and a member of the East Asia Summit, the Non-Aligned Movement, and the Commonwealth of Nations.