Mr Brown said he had asked the Labour Party to begin preparations for a leadership contest in which he will “play no part”.
His announcement on the steps of Downing Street was an attempt to woo the Lib Dem leader Nick Clegg by offering his own resignation as a key plank of any deal.
But Mr Brown also made it clear that he would expect to stay on as Prime Minister for a few more months in order to put in place his programme for economic recovery.
In the most dramatic twist since the election results were announced, Mr Brown admitted that Labour’s defeat “is a judgment on me.”
Full story: Gordon Brown to resign as Prime Minister as Labour and Lib Dems prepare for talks – Telegraph