Andy Burnham is calling for an urgent meeting with his leadership rivals to discuss fears Tories have infiltrated the party on a “large scale”.
The Shadow Health Secretary, one of four contesting the party leadership, has written to Labour’s General Secretary claiming “several thousand Tory infiltrators” could now be in the party.
Mr Burnham wants all the leader and deputy leader contenders to meet face-to-face as soon as possible to discuss how to tackle infiltration.
His concerns come after more than 1,000 people who signed up to the party as “registered supporters” are being denied a vote in the leadership election by Labour HQ amid fears of 'entryism' from other political parties.
Mr Burnham's suggestion was given short-shrift by the respective leadership camps of Jeremy Corbyn and Yvette Cooper.
Jeremy Corbyn's leadership team dismissed the letter, saying there needed to be a focus on policy, not process.
The letter, signed by Michael Dugher, Mr Burnham’s Campaign Chair and John Lehal, Campaign Director, welcomes the opening up of the election to the party’s “rank and file” but says: “There do however remain concerns about potential Tory infiltration on a large scale, with a Conservative MP, Conservative media commentators, and Conservative councillors all having been rejected.
“This suggests the 121,000 registered supporters could include several thousand Tory infiltrators, as well as supporters of other parties seeking to have a vote in the election.
“While we accept the party has processes in place, there is potentially more that can be done by the party nationally and regionally as well as by local CLPs to exclude such infiltrators.”
It continues: “To wait till 1 September for the next conference call with the teams when there are so many concerns is allowing the issue to drift, and potentially leaving insufficient time for the party to act.
“We are therefore writing to ask you to call an urgent meeting of candidate teams early next week to discuss this matter further, to brief us on progress being made, and to consider recommendations from the campaign teams.
This meeting should include representatives of all leadership and deputy leadership campaign teams, and should be a face-to-face meeting with those unable to participate joining by phone. We also believe that representatives of the Procedures Committee should be in attendance at the meeting.”
A spokesperson for Mr Corbyn, seen as the frontrunner in the campaign, gave their full support to the party management in the way it was carrying out the election.
The spokesperson 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. Whilst 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 party’s procedures committee will deal with process and campaigns can and should raise their issues with them directly – but the candidates need to face towards a country that feels insufficiently connected to our party.
An Yvette For Labour team spokesperson said Ms Cooper had spent the day in the South West "talking to members about the future of the Party and how Labour win again."
The spokesperson added: "The Labour Party has to do strong checks and follow up any evidence of people who do not support the Labour Party trying to vote in this election. But Yvette is focusing on winning arguments and votes not legal challenges. Yvette will continue to fight for every vote in this election - because there is so much at stake for the Labour Party and the country."
A Labour spokesperson said: “We hold regular meetings and calls with candidate teams to update them on the process and will continue to do so.”
This morning, former Labour MP Andrew MacKinlay claimed the party would not be ‘purging’ supporters if a candidate other than Jeremy Corbyn was set to win the leadership contest.