He served as Parliamentary Secretary to Prime Minister Jean Chrétien from 2000 to 2002.
In 2002, he was named Secretary of State for Central and Eastern Europe and the Middle East, and served as Minister of State for International Trade from 2003 to 2004 under Prime Minister Paul Martin.
Gar was defeated by the Elgin-Middlesex-London Conservative candidate Joe Preston in the 2004 election.
Shortly afterwards, Knutson joined Borden Ladner Gervais LLP, Canada's largest law firm, practicing in the area of government relations and public policy.
Knutson attempted to stage a political comeback in the 2007 Federal Liberal nomination in the riding of Ottawa—Orléans, but lost to former MP Marc Godbout.