Rebel MP was whip under Major

As a former Tory whip, Derek Conway knows all the tricks of the smoke-filled backrooms.

His experiences in the whips' office during the turbulent years of John Major's premiership helped to form his antipathy to Iain Duncan Smith for his role in the Maastricht rebellion, which crippled the Conservative administration.

The MP for Old Bexley and Sidcup has been increasingly critical of Mr Duncan Smith in recent days, and many in the party had expected he would add his name to the list of those demanding a vote of confidence in the leader.

Mr Conway was a key figure in David Davis's leadership bid after the 2001 general election. But yesterday he was careful to emphasise that any one of half a dozen people from the Conservative frontbench would be suitable for the job of leader.

The 50-year-old is a well-liked figure at Westminster. Proud of his roots in the North-east, he was brought up in Gateshead and cut his political teeth on Tyne and Wear council, which he led between 1979 and 1982. He served as a major in the Territorial Army, and has been chief executive of the Cats Protection League since 1998.