GORDON Brown announced tonight he was quitting as Labour leader as he revealed that Nick Clegg had requested formal talks with his party over a future government.

Mr Brown said he was asking the Labour Party to call a leadership election in which he would play no part.

He said he hoped the new leader would be in place in time for the autumn party conference.

He also said he was to press ahead with "formal discussions" with the Liberal Democrats after the request from Mr Clegg.

In a statement in Downing Street, Mr Brown said it was "sensible and in the national interest" to respond positively to the request.

He said the Cabinet would meet soon and a "formal policy negotiation process" would be established.

The Prime Minister said: "The reason that we have a hung parliament is that no single party and no single leader was able to win the full support of the country.

"As leader of my party I must accept that as a judgment on me. I therefore intend to ask the Labour Party to set in train the processes needed for its own leadership election.

"I would hope that it would be completed in time for the new leader to be in post by the time of the Labour Party conference.

"I will play no part in that contest, I will back no individual candidate."

In a day of high drama at Westminster after it first appeared that the Liberal Democrats were close to agreement with the Tories about a power-sharing deal, Mr Brown said his aim was to ensure a "stable, strong and principled government" was formed.

The Liberal Democrats thought they should first talk with the Conservatives, he said.

"Mr Clegg has just informed me that while he intends to continue his dialogue that he has begun with the Conservatives, he now wishes also to take forward formal discussions with the Labour Party.

"I believe it is sensible and it's in the national interest to respond positively.

"The Cabinet will meet soon. A formal policy negotiating process is being established under the arrangements made by the Cabinet secretary similar to the negotiations between other parties.

"The first priority should be an agreed deficit reduction plan to support economic growth and a return to full employment."

The move comes after Liberal Democrat MPs demanded clarification of key policy areas under discussion with the Tories.

Mr Brown said: "There is a progressive majority in Britain and I believe it could be in the interests of the whole country to form a progressive coalition government.

"In addition to the economic priorities, in my view, only such a progressive government could meet the demand for political and electoral change which the British people made last Thursday.

"If it becomes clear that the national interest, which is stable and principled government, can be best served by forming a coalition between the Labour Party and the Liberal Democrats, then I believe I should discharge that duty, support that government which would, in my view, command a majority in the House of Commons in the Queen's Speech and any other confidence votes.

"But I have no desire to stay in my position longer than is needed to ensure the path to economic growth is assured and the process of political reform we have agreed moves forward quickly."