Spidla was not affiliated with a political party until 1989; however, he was a member of Civic Forum and was one of the founding members of the Social Democratic Party (CSSD). In 1996 he was elected to the House of Deputies (lower house of Parliament), and was appointed chairman of the Parliamentary Committee for Social Policy and Health Care. He was appointed Deputy Prime Minister and Minister of Labor and Social Affairs in 1998, and was given the task of coordinating the work of the Ministry of Health, Ministry of Education, Youth and Sports, the Ministry of the Environment, and the Ministry of Culture. Former Prime Minister Milos Zeman tapped Spidla as his likely successor as party leader and prime minister in early 2001. Spidla became the leader of the CSSD in April 2002, and was named prime minister on 12 July after parliamentary elections were held in June.