Labour leadership: Liz Kendall calls for voting pact with Burnham and Cooper to prevent Jeremy Corbyn win

Exclusive: Ms Kendall urges supporters to vote for three of the four candidates

Liz Kendall has called for a voting pact with Andy Burnham and Yvette Cooper, her rivals for the Labour leadership, in an attempt to stop the left-wing front-runner Jeremy Corbyn winning the race (PA)

Liz Kendall has called for a voting pact with Andy Burnham and Yvette Cooper, her rivals for the Labour leadership, in an attempt to stop the left-wing front-runner Jeremy Corbyn winning the race.

In an interview with The Independent, Ms Kendall urged her supporters to vote for only three of the four candidates and to mark either Mr Burnham or Ms Cooper as their second and third preferences. She asked them not to give any of their votes to Mr Corbyn.

Under Labour’s preferential voting system, if no candidate wins more than 50 per cent of the votes, the bottom one drops out and the second preferences of their backers are reallocated. With Mr Corbyn set to benefit most from a last-minute surge of recruits that will give more than 600,000 people a vote, an anti-Corbyn alliance by the three mainstream candidates is now seen as the only way to stop him pulling off a remarkable victory on 12 September. The first ballot papers will be sent out today.

Moderate Labour MPs expressed concern that as leader, Mr Corbyn would force them to vote for his left-wing agenda in the Commons after he outlined plans to give party members more influence over policy. MPs fear they could be deselected before the 2020 election if they do not toe the line.

Ms Kendall said: “I will be using my second and third preferences….It won’t be for Jeremy. I will be strongly urging all of those who are putting me as their first preferences to use their second and third preferences.”

Polls show the Blairite candidate in fourth place but voting choices of her backers could prove important. “It is really important that people use three preference votes,” said Ms Kendall. “I have set out very clearly where I differ with all the candidates but our differences with Jeremy’s kind of politics are far greater.”

Ms Kendall will not reveal whether she will make Mr Burnham or Ms Cooper her second choice. “The main thing people need to consider is who is the best placed person to win against Jeremy,” she said.

However, some of Ms Kendall’s prominent backers will make Mr Burnham their second preference. There has been tension between the Kendall and Cooper camps, with Ms Cooper’s team accused of drawing attention to Ms Kendall being childless and accusing her of “swallowing the Tory manifesto.”

John Woodcock, an MP and senior member of the Kendall team, told his Barrow and Furness party members in a letter: “After giving it much thought, I have decided to give my second choice to Andy Burnham and third to Yvette Cooper. It was a difficult decision because I think that Yvette is a strong candidate….Most importantly though, I think Andy is the candidate who has the best chance of finishing ahead of Jeremy Corbyn.”

Gloria de Piero, the shadow Equalities Minister, and backbencher Simon Danczuk, who are backing Ms Kendall, will also name Mr Burnham as their second preference.

But some Kendall supporters will opt for Ms Cooper as their number two and put Mr Burnham as number three. They include Tristram Hunt, the shadow Education Secretary, who has told his party members in Stoke-on-Trent: “I will not be awarding any of my preferences to Jeremy Corbyn.” Mr Hunt admitted there was “obvious popular enthusiasm for him in some parts of the movement,” but said his leadership could pose a “very real risk” to the party’s future.

Ms Kendall’s move was welcomed by Ms Cooper’s team, who insist their candidate has the best chance of overtaking Mr Corbyn. But the Burnham camp reacted coolly. It is convinced that it is in second place and capable of winning without organised tactical voting.

There is growing tension between the Burnham and Cooper teams as they battle to become the “stop Corbyn” candidate. After Mr Burnham criticised Ms Cooper for a fighting speech in which she tackled “Corbynmania” head on, her allies accused Mr Burnham of “pandering to Corbyn” and ignoring the vital task of taking votes away from him to stop him winning a knockout victory with more than 50 per cent of the votes.

Ms Cooper won praise for a powerful speech in Manchester in which she said Mr Corbyn offered “old solutions to old problems.” Describing his politics as “subversive”, she claimed his policies were neither credible nor radical. She told her audience: “So tell me what you think is more radical. Bringing back Clause IV, spending billions of pounds we haven’t got switching control of some power stations from a group of white middle-aged men in an energy company to a group of white middle-aged men in Whitehall, as Jeremy wants? Or extending SureStart, giving mothers the power and confidence to transform their own lives and transform their children’s lives for years to come?”

The shadow Home Secretary declared: "We can't just luxuriate in our own righteousness out on the sidelines. That's not a luxury the most vulnerable in Britain can afford. It's not enough to be angry at the world. We're the Labour Party, we have a responsibility to change the world or what's the point of us at all?"

But Mr Burnham refused to join the criticism, saying those attacking Mr Corbyn were “misreading the mood of the party.” He pledged: “I will be keeping it positive.”

Mr Corbyn said critics who have resorted to personal abuse and attacks on his character are "nervous about the power of democracy". He added: “Probably 600,000 people will be taking part in this process in the next month. What is there not to like about that?”