Tristram Hunt has said he does not plan to run for Labour Party leader, instead giving his backing to Liz Kendall.

Mr Hunt said he could not be confident of enough support from fellow MPs to launch a bid.

He also questioned the timescale of the leadership process, saying it had been "almost decided" within five days of the election.

Ms Kendall, Andy Burnham, Yvette Cooper and Mary Creagh have put themselves forward for the leadership.

Candidates must get the support of 35 of the party's MPs in order to stand in the contest, which will be decided in September.

In a speech in London, Mr Hunt said he had "made a lot of calls" to other MPs, but said many of them were already committed to "just a small number of candidates", saying he found it surprising this had happened so soon after the "devastating" election defeat.

Ms Kendall, he said, would be able to confront the "big challenges" facing Labour and would have the "leadership mettle" to succeed.

Responding to his endorsement, Ms Kendall said her fellow MP was "a big talent" and she was "delighted" to have his support.

Image copyright PA Image caption Four candidates have already declared

In his speech, Mr Hunt also criticised Ed Miliband's "timid" approach to the election.

Mr Miliband, who resigned after Labour's election defeat, was said to have pursued a 35% strategy - focusing on core Labour voters and disaffected Lib Dems and hoping UKIP would sink the Tories.

Mr Hunt said Labour needed a "100% strategy" that was "broad-based" and "forward-looking".

'Out of step'

He urged the party not to "turn inwards" and said merely "rediscovering Labour's beating heart" would not revive the party's electoral fortunes.

He suggested that what was needed was a return to the combination of economic discipline and social renewal that won Labour three election victories under Tony Blair, describing this as a "winning argument".

"Not since 1983 have we been so out of step with the prevailing mood of the nation," he told the event at the think tank Demos.

"But worse still, for perhaps the first time, we now face an electoral battle across three distinct fronts: the rise of nationalism in Scotland, a lack of trust in our traditional English heartlands and loss of confidence in Middle England."

Mr Hunt, a historian and the MP for Stoke-on-Trent Central, said Labour had "collectively dithered" on the question of devolving powers to other parts of England.

Image copyright AP Image caption Mr Hunt took aim at Ed Miliband's (right) approach to the election

"The shadow cabinet was not united" when the Conservatives proposed new powers for Greater Manchester and other northern cities, he said, calling for "big and bold English devolution".

Mr Hunt also said Labour should consider freezing or reducing child benefit for school-age children to pay for a "universal right to free childcare" for all parents of two-year olds.

And he said the party "could and should" have prepared for tougher economic conditions during its time in government.

All the leadership contenders are setting out their stalls, with Mr Burnham - described as the "unifying" candidate by his supporters - calling for a referendum on the EU to be brought forward to 2016 and for an end to new free schools.

Ms Cooper, meanwhile, has said Labour must rethink its approach to business by dropping its opposition to corporation-tax cuts and consulting more closely with business leaders before developing new policies.

'No quick fix'

Ms Kendall has also won the backing of former minister Pat McFadden, who said she best understood that "Labour wins when it gives a positive, hopeful, optimistic story of the country's future as well as just collecting a set of causes and grievances".

Labour's deputy chairman Jon Trickett - a shadow minister - said he was disappointed that Mr Hunt would not be standing.

He echoed the shadow education secretary's comments on the need for more diversity in the leadership race.

"All the MPs and all the party should think very carefully about the danger that we finish up with only one, two or three candidates, probably from similar points of view and similar backgrounds too," Mr Trickett said.

Image caption New MP Sir Keir said Labour needed to be "brave enough" to ask difficult questions about itself

Sir Keir Starmer, the former Director of Public Prosecutions who is now a Labour MP, told the BBC that he had not decided who to back but the party needed a "fully-formed leader able to hit the ground running from the very start".

Amid concerns that established candidates are hoovering up support among MPs, he told Newsnight "people are very quick to tell you who is going to win" but it was a long campaign and those standing needed to face up to the harsh realities of Labour's position.

"We cannot paper over the cracks," he said.

"There is no point in a quick fix which presents itself as unity but is not unity... We need to have that open debate and be brave enough to ask difficult questions and to see what answers are coming to us from outside our party."

A number of other prominent Labour MPs, including Dan Jarvis, Alan Johnson and David Lammy, have ruled themselves out of the race, while Chuka Umunna withdrew three days after entering the contest, citing concerns about media scrutiny of his family.