It is the leading opposition party of Turkey, with 178 out of 550 seats in the Great National Assembly of Turkey. Before 2002 it had been the governing party.
It was founded in 1923 by Mustafa Kemal Atatürk, and was the sole political party in Turkey until 1946. It is currently led by Deniz Baykal.
See also: Politics of Turkey, List of political parties in Turkey.