Conservative Party

He joined the Conservative Research Department in 1966, becoming head of the economics section in 1974. He stood for Parliament at the February 1974 general election in Rugby but lost by 6,154 votes to Labour's William Price.

He was elected as the Treasurer of the Daventry Conservative Association in 1976 and subsequently its Chairman from 1979 to 1983. He became a political advisor to the Minister of Agriculture, Fisheries and Food Michael Jopling for two years from 1984.

House of Commons

Boswell was chosen to contest the Daventry constituency after the sitting Conservative MP Reg Prentice announced his retirement. He was elected as the Conservative MP for Daventry at the 1987 general election with a majority of 19,690 and held the safe seat comfortably until his retirement from the House of Commons.

Tim Boswell's Westminster career began unsurprisingly as a Member of the Agriculture Select committee in 1987. He became the Parliamentary Private Secretary to the Financial Secretary to the Treasury Peter Lilley in 1989. Tim Boswell entered John Major's government in 1990 as an Assistant Government Whip, following the 1992 general election he was promoted within the Whip's Office and became a Lord Commissioner to the Treasury.

In December 1992, Tim Boswell was appointed Parliamentary Under Secretary of State at the Department of Education and moved in the same position at the Ministry of Agriculture, Fisheries and Food until the Major government fell at the 1997 general election.

In opposition Boswell was a spokesman on the Treasury in the immediate aftermath of the 1997 election defeat and became a spokesman on Trade and Industry under William Hague, before speaking on Education and Employment in 1999 until after the 2001 general election. He became the spokesman for Work and Pensions under the leadership of Iain Duncan Smith, moving briefly to speak on Constitutional Affairs in 2003 under Michael Howard and back to Work and Pensions in 2004, where he remained following the 2005 general election.

On 31 March 2006, Boswell announced his intention not to contest the subsequent general election, provided it did not take place unexpectedly soon. The Daventry seat was split in two at the 2010 general election, with the northern portion becoming part of a new Daventry constituency and the southern part becoming part of a South Northamptonshire constituency.

In May 2009, he was listed by The Telegraph as one of the "Saints" in the expenses scandal.^[6]

After his retirement from the House of Commons the seat remained Conservative under Chris Heaton-Harris.

House of Lords

He was raised to the House of Lords as a Conservative Life peer being created Baron Boswell of Aynho, of Aynho in the County of Northamptonshire on 8 July 2010.^[1] In May 2012, he resigned the Conservative whip after being made Principal Deputy Chairman of Committees in the House. He also became Chairman of the European Union Committee.^[7][8]