WILLIAM Hague last night quit as foreign secretary and announced he will stand down as Richmond MP at next year's general election.
The shock news came as the Prime Minister cleared the way for a younger generation - and more women - to take their places at the Cabinet table.
Mr Hague, 53, will take up the lesser role of Leader of the Commons and spearhead the Tory campaign in key constituencies, particularly in the North, until he leaves his safe seat after 26 years.
He said: "I wish to thank my constituents in Richmond, Yorkshire, one of the greatest places on earth, for their emphatic support through thick and thin over such a long period." "I will serve them with unabated energy between now and the general election, and I look forward to supporting my eventual successor.
"I am delighted to be able to serve as Leader of the House of Commons, and to be able to campaign for Conservative candidates across the country. I want to finish in frontline politics as I began - speaking in Parliament and campaigning on international causes I believe in."
"By the time of the general election next year, I will have served 26 years in the House of Commons and it will be 20 years since I first joined the Cabinet.
"In government there is a balance to strike between experience on the one hand and the need for renewal on the other, and I informed the prime minister last summer that I would not be a candidate at the next general election."
David Cameron needs to find a senior figure to be the UK's next European Commissioner, but Mr Hague indicated that he wanted to concentrate on his writing career.
"After the general election I will return to my writing, while still giving very active support to the Conservative Party and campaigning on international causes I believe in," he added.
Mr Cameron said: "William Hague has been one of the leading lights of the Conservative Party for a generation, leading the party and serving in two cabinets.
"Not only has he been a first class foreign secretary - he has also been a close confidante, a wise counsellor and a great friend.
Mr Hague pictured earlier this year with UNHCR Special Envoy Angelian Jolie laying wreaths at the Genocide Memorial in Kigali, Rwanda
"He will remain as First Secretary of State and my de facto political deputy in the run up to the election - and it is great to know that he will be a core part of the team."
Defence secretary Philip Hammond is expected to be named as Mr Hague's replacement as foreign secretary.
The announcement followed the widely expected decision by Ken Clarke to retire at 74, ending a career in government stretching back to 1972. Veteran MP Sir George Young also resigned as chief whip.
Sixteen year old Rother Valley schoolboy William Hague meets Margaret Thatcher at the 1977 Conservative Party conference in Blackpool.
Downing Street said the Prime Minister had also accepted the resignations of universities minister David Willetts and energy and climate change minister Greg Barker.
Andrew Robathan quit as a minister in the Northern Ireland Office, while Hugh Robertson resigned from the Foreign Office.
David Jones was sacked as Welsh Secretary while Dominic Grieve lost his job as Attorney General and Owen Paterson was axed as Environment Secretary. Policing minister Damian Green also went.
Mr Cameron is expected to promote a host of younger talent, including employment minister Esther McVey, education minister Liz Truss and ministerial aide Penny Mordaunt.
Others tipped for promotion include Margot James, Amber Rudd and Harriett Baldwin. Former defence secretary Liam Fox could also make a comeback to the political front line nearly three years after quitting in a row over his special adviser.