He entered politics in 1995 as deputy of Isparta from the Motherland Party. In 1997–1998, Erkan Mumcu served as secretary general and in 1998–1999, he was vice president of the party. He became a member in the coalition government of Bülent Ecevit as Minister for Tourism serving from May 28, 1999 to August 8, 2001.
After a dispute with Recep Tayyip Erdoğan, he resigned on February 15, 2005, and joined the Motherland Party again. Erkan Mumcu was elected 6th president of ANAP at the extraordinary party congress on April 2, 2005. On October 25, 2008, Mumcu resigned the leadership of the Motherland Party.