A North Yorkshire MP has announced he will be retiring from Parliament at the next General Election.
Phil Willis took over the Harrogate and Knaresborough seat in 1997
Liberal Democrat Phil Willis won the formerly safe Conservative seat of Harrogate and Knaresborough against ex-Chancellor Norman Lamont in 1997.
In a letter to his local party he said he always wanted to bow out of politics when he was "at the top".
Former head teacher Mr Willis, who is 65, spent eight years as Lib Dem education spokesman.
He is now chairman of the House of Commons Select Committee on Science and Technology.
He won his North Yorkshire seat with more than 50% of the vote in three successive elections.
In his letter to the local party Mr Willis wrote: "It has always been my aim to bow out of frontline politics at the top and when I am doing the job as I want to do it."
Lib Dem leader Sir Menzies Campbell said: "Phil Willis has been a much-valued colleague and friend since he was elected to the House of Commons.
"His direct, no-nonsense analysis of political issues has been an abiding characteristic, together with his eloquent and tireless advocacy on behalf of his constituents."