LABOUR’S chaotic leadership election looked even more likely to end in the courts yesterday after both Jeremy Corbyn and Andy Burnham suggested they might challenge the result.

In a letter to Labour’s general secretary Iain McNichol, Burnham’s campaign chief, Barnsley MP, Michael Dugher, claimed “several thousand” Tories and others had paid the £3 supporters’ fee and registered for a vote.

Although not explicitly stated in the letter, Dugher believes voters are deliberately choosing Corbyn over the other candidates in a bid to sabotage Labour’s electoral chances.

However, Labour's acting leader Harriet Harman insisted that the result will stand, whoever is named the victor.

She said the leadership ballot would be conducted in a “rigorous, fair, robust and even-handed way”, but added: “Whoever is elected, they will be legally elected and the result will stand.”

Currently Corbyn is, by some considerable distance, the favourite to win the race. In his letter, Dugher said Labour should be doing more to get rid of any

“rogue voters”.

He wrote: “We are also concerned that given the party’s limited resources and the effort required to investigate applicants, this could result in the integrity of the contest being called into question, and the outcome subject to legal challenge,” he said.

Since the General Election, more than 120,000 people have signed up as supporters, along with over 189,000 members of unions and other affiliates. More than 600,000 should have a vote in the race.

Corbyn seemed to suggest at a rally on Thursday night that his team could challenge the result if it seemed he was losing out.

“If there are significant numbers rejected in apparently an unfair way, then of course that must be looked at again and challenged” he said. “But the issue really is, let’s be happy about getting 600,000 people taking part in an election.”

Yesterday afternoon his team said they had “confidence” in the way the election was being run and accused Burnham of focusing on process rather than political issues.

A Corbyn spokesman said: “This latest internally faced intervention is an attempt to distract the leadership election onto ‘process’ rather than real political issues, such Jeremy Corbyn’s commitment to move on from the legacy of the Iraq war with an apology. This is because Jeremy Corbyn is setting the political agenda.

“The purely internal procedural obsession falls short of the outward debate the party needs. While some issues have been raised, we do have confidence in management of the process by elected members of Labour’s NEC and the general secretary.”

The spokesman continued: “Every day the campaigns focus on how Labour runs its elections is a day lost in talking about how to win the real elections that count, the General Election of 2020, and other vital elections along the way.”

A Labour spokesman said: “We hold regular meetings and calls with candidate teams to update them on the process and will continue to do so.

“The Labour Party has a robust system to prevent fraudulent or malicious applications. All applications to join the Labour Party as a member, affiliate or supporter are verified and those who are identified by our verification team as being candidates, members or supporters of another political party will be denied a vote.”

It is thought around 80 Labour party staff are vetting new supporters to make sure they are not campaigners for other parties.

The party yesterday confirmed that those purged would not be eligible for a refund of their £3. A spokeswoman told The National this was an administration fee and that this was explained fully up front. She also denied rumours circulating on Twitter that anyone requesting a refund would need to pay a £25 charge.

Last night, Yvette Cooper insisted she was still in the race.

Speaking to activists in Devon, Cooper said: “Don’t write our party off based on some close polls. Surely May 8 taught us a bit of scepticism about poll results.

“Don’t think it’s a done deal because of the bookies’ odds. Paddy Power hasn’t got a hotline to the hearts of Labour Party members

“Hundreds of thousands of people are yet to even open their ballot papers. Many thousands are still undecided.“This is no time for hubris from those who think they are winning. And no time for defeatism from those who believe we need another way.”

The MP also attacked Corbyn, accusing him of offering “a fantasy – easy to sell, but impossible to realise”.

And fellow contender Liz Kendall insisted that she was the candidate most feared by Tory MPs.

In a graph released to supporters, she claimed a poll of Tory MPs showed that they wanted to Jeremy Corbyn to win.

Corbyn: I will apologise for the Iraq War on behalf of Labour if I become leader