He served as the chairman of the Senate standing committee on National Security and Constitutional reforms, between 2008 till 2013 and was responsible for the drafting of Amendment XVIII which turned Pakistan from a semi-presidential to a parliamentary republic. He has been elected a senator for six times since 1993 from the Sindh Province. He was a close aide to Benazir Bhutto who had appointed him the party’s deputy secretary general in 1997 and leader of the opposition in the Senate in 2005.