Sonia Gandhi campaigned for the Congress in the 2004 Lok Sabha elections. Congress managed to get a tally of 141 seats, largely due to her charismatic presence during the campaign. Travelling the length and breadth of the country in a hurricane election tour, Sonia caught the imagination of the masses, by her emotional speeches. She was able to achieve an unexpected election success. She contested Lok Sabha elections from Bellary, Karnataka and Amethi, Uttar Pradesh in 1999. In Bellary she defeated veteran BJP leader, Sushma Swaraj. In 2004 and 2009, she was re-elected to the Lok Sabha from Rae Bareli in Uttar Pradesh. The election results provided her with a unique opportunity to become India's Prime Minister. She sacrificed the post in favour of Dr. Manmohan Singh.
Sonia Gandhi is the Chairperson of the National Advisory Council (NAC). Sonia Gandhi had announced her resignation from the Lok Sabha and also as chairperson of the National Advisory Council under the office-of-profit controversy and the speculation that the government was planning to bring an ordinance to exempt the post of chairperson of National Advisory Council from the purview of office of profit. She was re-elected from her constituency Rae Bareilly in May 2006 by a huge margin of over 400,000 votes. She addressed the United Nations on 2 October 2007, Mahatma Gandhi's birth anniversary which is observed as the international day of non-violence after a UN resolution passed on 15 July 2007. Under her leadership, India returned the Congress-led-UPA to a near majority in the 2009 general elections with Manmohan Singh as the Prime Minister. The Congress itself won 206 Lok Sabha seats, which was the highest total by any party since 1991.Sonia Gandhi advocated austerity for all the congress MPs and set an example by travelling in economy class on her 14 September 2009 travel from New Delhi to Mumbai. She saved Rs 10,000. She also advocated for contribution of 20% of MPs salary for the drought affected victims in India.