LIZ Kendall has ruled out standing aside in the Labour leadership contest to help block the growing challenge from hard left candidate Jeremy Corbyn.
The shadow care minister insisted she will fight to the very end and warned that a victory by the veteran backbencher would be a “disaster” for the party.
Ms Kendall is reported to be under pressure to quit the contest to allow the moderate vote to rally behind one of her two centrist rivals - Andy Burnham and Yvette Cooper.
Asked if she would step aside, Ms Kendall told BBC News: “No. You never stop fighting for what you believe in. I will be fighting for what I believe in till the very end.”
She added: “It would be a disaster. Turning back to the politics of the 1980s, which saw us suffer defeat after defeat does nothing to help the people we all came into politics to serve.”
Ms Kendall has ruled out serving in a Corbyn shadow cabinet but insisted she would not leave the party if he wins in September.
“I’ll never ever do that,” she said. “That would be like me leaving my family.”
Amid bitter recriminations at the top of the party after one opinion poll put Mr Corbyn on course for a shock victory, Lord Mandelson warned that Labour’s future as a viable party of government was under threat.
But former deputy prime minister Lord Prescott rejected claims that it would be a “disaster” for Labour if the Islington North MP became leader and said it was Tony Blair’s invasion of Iraq which had undermined support for the party.
He said the former prime minister’s suggestion that anyone whose heart told them they should back Mr Corbyn should “get a transplant” was “totally unacceptable”.
Lord Mandelson, one of the key architects of New Labour, said the party was struggling to deal with the “terrible legacy” left by Ed Miliband.
“Those of us who stayed and fought to save the Labour Party in the 1980s will be experiencing a growing sense of deja vu,” he told The Times.
“The last five years have left us with a terrible legacy to overcome with the existence of the Labour Party as an effective electoral force now at stake.”
Mr Burnham last night made a surprise declaration that he would be prepared to serve in the shadow cabinet if Mr Corbyn became leader.
Ms Cooper left the door open to remaining on the front bench but Ms Kendall ruled out taking a position with a flat “no”.
During a leadership hustings on LBC, she warned that a Corbyn win would put the party out of power for “a generation”.
“I think it would be disastrous for the party, it would be disastrous for the country, we’ll be out of power for a generation,” she said. “I don’t want to be a party of protest and I wouldn’t be able to stop myself from making that case.”
Ms Cooper has again refused to rule out serving under Mr Corbyn - although she said she would not stand in the shadow cabinet elections if he became leader.
“If you are involved in politics and believe in the Labour Party, you shouldn’t just take your bat and ball home,” she told the BBC Radio 4 Today programme.
She admitted the party had been damaged by the decision to abstain in the Commons vote on the Government’s welfare reforms - prompting 48 MPs to rebel, including Mr Corbyn.
“It was a complete mess. We voted for an amendment which would have blocked the Bill, would have stopped it in its tracks, would have ditched the whole thing, but that got completely lost. The whole thing has been badly handled,” she said.
Ms Cooper denied claims that she had failed to set out a distinctive position, insisting it was possible to campaign for a fairer society and a stronger economy.
“At the moment the Labour Party is being posed with this false choice - choose between your head and your heart, choose between your values, stick to your principles, be unelectable, or, alternatively, ditch all your principles in order to be elected. We can do both,” she said.
She drew a comparison with former prime minister Harold Wilson’s famous “white heat of technology” speech.
“He won elections with it - the white heat of technology - let’s have the white light of the digital age. That is something we can pull behind,” she said.