Michael joined the Labour Party while at school, and has held numerous voluntary posts within the Party. As Worcester’s MP, he introduced the Wild Mammals (Hunting with Dogs) Bill in 1997 to ban hunting. The Bill received massive backing both in Worcester and in Parliament. The Bill became law in 2004.

In 1999 he introduced the School Crossing Patrol Bill to improve road safety, following a local campaign in Worcester. That Bill was adopted immediately by the Government and became law in 2000.

In 2004 he re-introduced a Bill to give all pensioners free bus travel. The measure was unopposed but ran out of Parliamentary time. In March 2005 however, the Government incorporated the measure into the Budget, and took effect from April 2006.

After the General Election in 2001 he was appointed Parliamentary Private Secretary to the Lifelong Learning and Higher Education Minister at the Department of Education and Skills. In May 2005 he was appointed Parliamentary Private Secretary to Peter Hain, Secretary of State for Northern Ireland.

In May 2006, he was telephoned by the Prime Minister and offered his first ministerial appointment in the Government Whips' Office. He had responsibilities for Northern Ireland and for Constitutional Affairs. In July 2007 he was re-appointed as a Government Whip, and given responsibility for the Department of Children, Schools and Families and the Department of Innovation, Universities and Skills.

Following the Government reshuffle in 2008, he was asked by the Prime Minister to serve as a Minister for International Development, a post he currently holds.