Labour must pick its next leader from the emerging generation of MPs and long-term shadow cabinet favourites for the job should stand aside, a former cabinet minister has said.
Lord Hutton has suggested people such as Andy Burnham and Yvette Cooper should make way to allow younger challengers to fight for Ed Miliband's old job.
Lord Hutton said the "bitter" defeat at the polls had set the party back 30 years, blaming the lack of public appetite for an "old school socialist menu".
Lord Hutton also ruled out a return for David Miliband who was beaten to the leadership by his brother in 2010.
Among those tipped to throw their hats in the ring include Chuka Umunna, Liz Kendall and ex-soldier Dan Jarvis - all of whom have been in the Commons for five years or less.
The National Executive Committee (NEC) will meet early next week to set a timetable for a contest to replace both him and deputy leader Harriet Harman who will quit that post after steering the party through the interim.
Some in the party have urged a swift process to deny the Conservatives a chance to define the agenda, but others - including shadow education secretary Tristram Hunt, a potential candidate - have urged a longer period of reflection.
Tony's Blair's former spin doctor Alastair Campbell also think the party should take time to choose a new leader.
Writing in the Daily Mirror, he said: "I think this time we should take our time picking a leader. We need a fundamental, honest debate on who we are and what we represent. We've got to include more people in shaping what we are, what we stand for.
"I'm not suggesting a return to the New Labour playbook, but we need to find the leader, the strategy, the right politics, for very different times.