Bernard Jenkin has been relieved of his role in charge of the Conservative A-list of potential parliamentary candidates.
He has been replaced by John Maples, with the former Treasury minister becoming deputy chairman with responsibility for candidates.
The move comes as part of a reshuffle of the shadow cabinet, with David Cameron promoting eight new MPs to the Tory's front bench.
James Brokenshire, Greg Clark, Robert Goodwill, David Jones, Mark Lancaster, Anne Milton, Ed Vaizey, and Shailesh Vara were all elected in the 2005 election. They move to positions in the in the shadow Department for Communities and Local Government (DCLG) , whips' office, Welsh office, and the shadow Department for Culture Media and Sport (DCMS). Mr Vara became shadow deputy leader of the House.
Mr Jenkin was involved in a controversy this week, after he reportedly told an ethnic minority Tory candidate that he had little chance of becoming an MP.
However, the Conservative party has rejected claims that the two incidents were linked and said the MP for Essex North had been offered another front bench post.
Announcing the new shape of his team, Mr Cameron said Mr Jenkin had done a "tremendous job" with the A-list.
The Conservative A-list is designed to increase the proportion of women and ethnic minority candidates handed winnable Tory seats at the next election.
Mr Cameron said Mr Maples - who has held positions as shadow health secretary, opposition defence spokesman, and shadow secretary of state for foreign affairs - had taken over the role because a new person was needed to "take it forward".
Mr Jenkin said it was the "right time" to move on in a letter to the Tory leader, adding: "Having served on the opposition front bench for nearly ten years, mostly in the shadow cabinet, I would prefer to return to the backbenches."
He was elected to parliament in 1992 as MP for North Colchester, since 1997 he has served as MP for North Essex and was appointed deputy chairman of the party with responsibility for candidates in December 2005.
But Mr Jenkin was not the only MP returning to the back benches, with Tim Boswell, Mark Field, Malcolm Moss and Andrew Turner also leaving the shadow cabinet.
The changes also see Henry Bellingham join the shadow Department for Constitutional Affairs (DCA), Anne McIntosh become a shadow education minister, Maria Miller become shadow family welfare minister, and Andrew Selous become a shadow work and pensions minister.
For the full list of the new Conservative front bench, go to www.conservatives.com/.