JEREMY Corbyn has recorded a massive 22-point lead in the battle to replace Ed Miliband as leader of the Labour party.

According to private polling by the Labour party leaked to the Daily Mirror, Corbyn is now on 42 per cent of the vote, way ahead of nearest rival Yvette Cooper on 22.6 per cent, Andy Burnham on 20 per cent and Liz Kendall on 14 per cent.

Unsurprisingly, the veteran left-winger does not benefit from the second preference votes of the other three candidates. After those are taken into consideration Corbyn leads Cooper by only two per cent.

The Labour leadership battle still has over a month to go. Ballot papers are sent out on August 14, with the announcement on September 12.

Corbyn, who was already popular, has received something of a bounce in the polls since being attacked by former Labour leader Tony Blair last week. The ex-Prime Minister said anyone who wanted to go with their heart and vote Labour should have a heart transplant.

Yesterday, Corbyn and Kendall criticised the sexist nature of the contest.

Labour MP Helen Goodman previously claimed she would back Cooper as she was a “working mum” who “understands the pressures on modern family life”.

Supporters of Kendall, who has no children, saw it as a direct attack.

Speaking to Mumsnet, Kendall said the campaign had “felt a bit 1970s ... or even 1950s!” She continued: “I’m a feminist – I believe women should be judged by their ideas, their values, and what they have to contribute, not by what they wear, what they look like, or their family situation or relationships.

“We have a painfully long way to go before that’s the case.”

Corbyn replied: “I think people should be judged on the policies they’re enunciating and not on levels of bad attitudes or abuse that are heaped upon them by anybody else and some of our popular media.Actually, I don’t do personal, I’m more interested in ideas and politics.”

Previously Cooper had criticised the sexist nature of

Burnham’s campaign. She said: “Andy’s campaign seems to be calling for Liz and I to bow out and leave it to the boys, or suggesting that somehow women aren’t strong enough to do the top jobs.

“Liz has been asked about her weight, I’ve been asked on BBC Radio 4’s Woman’s Hour of all places about whether I can possibly do this job because of my husband, and any talk about me being a working mum has been used as a sexist way to divide Liz and I and criticise Liz for not having children.”

Yesterday saw Corbyn launch his women’s manifesto. The MP for Islington North promised to increase the number of female Shadow ministers in his cabinet to make sure that 50 per cent are women.

He also aimed to increase the number of female MPs in the Labour Party at the next election.

The interim leader of the party Harriet Harman moved to deny that the Labour leadership election was being overrun by supporters of other parties. New Labour rules mean that anyone can pay a one-off fee of £3 to become a supporter of the party and have a vote in the election.

Since the election, Labour claim that 20,000 new full members and 21,000 supporters have joined up throughout the UK. It is not known how many have joined up in Scotland.

Harman said: “We are policing the integrity of this process. My job is to ensure the rules for this election agreed in 2014 are properly applied. The system is designed to give people who are supporters of the party, but not necessarily a member, a say in choosing the leader of the Labour party.

“We have got an extensive verification system in place. We are doing everything possible to ensure the process is valid. Under the old system you could be a card-carrying member of another party and you still got a vote. We are now requiring people to say if they are Labour party members or supporters.”

Harman said supporters’ names were being given to local constituency Labour parties, which were asked to report back if someone was a fake or a known rival.