Britain's Labour Party will name a new leader on September 12 following the resignation of Ed Miliband in the wake of his shock election defeat last week, the party's executive committee said today.
Nominations will close on June 15, the party said.
The party's main spokespeople on business, Chuka Umunna, and on health, Liz Kendall, have already declared they will run for the post of leader.
Umunna, 36, would be the first ethnic minority leader of a major British political party but is seen by critics as too inexperienced, having been elected to parliament for the first time only in 2010.
Yvette Cooper, a former work and pensions minister, and Andy Burnham, a former health and culture minister, are also seen as possible frontrunners.
Divisions have emerged within the party over whether its campaign had been too left-wing or not left-wing enough, with former prime minister Tony Blair and "New Labour" supporters particularly critical.
Labour's new leader would then lead the party conference on September 27.
Prime Minister David Cameron's Conservatives won last Thursday's general election with 331 out of the 650 seats in the House of Commons against 232 for Labour.
"The general election saw the Labour Party suffer a serious defeat and over the coming weeks we need an open and honest debate on the right way forward," the party's interim leader Harriet Harman said.
Labour party leaders are elected by party and trade union members.
