Though Singh entered politics in the late 60s, the first few years of his political life lacked success and recognition, till he was initiated in the Jan Sangh, by BJP stalwart Bhairon Singh Shekhawat who is considered to be Jaswant's political mentor. He tasted success in his political career in 1980 when he was first selected for the Rajyasabha, the upper house of Indian parliament. He served as Finance minister in the short-lived government of Atal Bihari Vajpayee, which lasted just from 16 May 1996, to 1 June 1996. After Vajpayee became Prime Minister again two years later, he became Minister for External Affairs of India, serving from 5 December 1998 until 1 July 2002. Responsible for foreign policy, he dealt with high tensions between India and Pakistan. In July 2002 he became Finance Minister again, switching posts with Yashwant Sinha. He served as Finance Minister until the defeat of the Vajpayee government in May 2004 and was instrumental in defining and pushing through the market-friendly reforms of the government. He was conferred the Outstanding Parliamentarian Award for the year 2001. On 19 August 2009, he was expelled from BJP after criticism over his remarks in his book which allegedly praised the founder of Pakistan in his book Jinnah – India, Partition, Independence. His last major position was as Leader of Opposition in the Rajya Sabha from 2004 to 2009.