Andy Burnham is a fake, according to his former campaign chief who tells Labour leadership favourite to 'get real' in Facebook rant

Stuart Bruce ran Andy Burnham's campaign in the 2010 campaign, when he finished fourth

David Miliband, right, is embraced by his brother party leader Ed Miliband (Getty Images)

Andy Burnham has "created" a fake persona to win the Labour leadership race, according to his former campaign chief.

Stuart Bruce claimed his former boss had lurched to the left in order to sew up the trade union votes. In doing so, he had made winning the 2020 election less likely, he added.

Mr Bruce, who ran Mr Burnham's campaign in the 2010 leadership contest when he finished behind the two Miliband brothers and Ed Balls, warned Mr Burnham that reverting to the "real Andy" after winning the leadership election would be too late.

Ed Miliband narrowly beat his brother David in the 2010 leadership contest, thanks largely to the backing of the trade unions (Getty Images)

Mr Burnham is the bookies' favourite to be elected as Labour's new leader when the result is announced on September 12. He faces tough competition from Yvette Cooper and Liz Kendall.

Taking to Facebook to vent his frustration, Mr Bruce said: "I just wish we could see the real Andy. The real one I’d vote for in a flash. The new one has been created solely to win the leadership and in doing so is reducing what chance we have of winning the country.

“If the intention is to revert to the real Andy after winning then it’s mistaken as it won’t work.”

He later clarified his comments to The Sun: “He is doing everything he needs to get elected Labour leader when he should be trying to get elected PM.

“He is talking more to a trade union audience and forgetting he is capable of talking to a wider audience.”

Mr Miliband reformed the way the party elects its leader to reduce the powerful influence of trade unions in the vote, despite he himself benefiting from their block vote to narrowly beat his brother in the 2010 contest.

The current leadership race will be the first under one member, one vote system. Under the previous rules, trade union members were guaranteed one-third of the electoral college. The Parliamentary Labour party was given another third, while the remaining third went to Labour party members.

Each of the five contenders in the race must win the nomination of at least 35 Labour MPs to enter the ballot. Nominations close on Monday. The leading three contenders have secured sufficient backing but the two outsiders - Mary Creagh and Jeremy Corbyn - are yet to reach 35 nominations.