Jeremy Corbyn and Zarah Sultana admit losing data of 20,000 Your Party members in portal mix-up

In the latest blow to their new political group, the hard-left MPs announced that more than 20,000 people's data was lost after Ms Sultana launched a membership portal on September 18.

The portal's release started a row between the pair, with Mr Corbyn claiming he was seeking legal advice after an email sent out on that day contained a link to the "unauthorised" portal.

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Six days later, the former Labour leader "made amends" with Ms Sultana and released a new membership portal created by his team.

But the party now says it has lost the personal information and donations of those supporters who used the initial portal.

Donations gathered from the first portal currently sit in a bank account run by MOU Operations Ltd, a group set up to support the party's launch.

However, MOU had not been told about the launch of Mr Corbyn’s second portal, with directors reportedly "blindsided' by the action.

Bosses are now holding emergency meetings to discuss the the organisation's legal and financial responsibilities.

In an email sent to supporters on Monday, Your Party said: "We’ve come up against an issue that has proved frustratingly difficult to solve.

"Many of you joined Your Party via the membership portal promoted by Zarah on Sept 18. If that applies to you, you are a member of Your Party.

"But because your membership data is held by the company that took your payment, MOU Operations Ltd, we have had no way to access it or integrate you into our membership portal."

For those who have joined the group using Ms Sultana’s portal, Your Party has asked them to register again and select "I already paid" option in order to receive free membership for three months.

The email continued: "Over the past month, we have done everything possible to secure the transfer of your membership data.

"Both Zarah and Jeremy, along with Shockat, Adnan, Ayoub and Iqbal, have made written requests to MOU for the transfer to happen. But legal issues around ownership of the data – which are beyond Your Party’s control – have so far proved intractable.

"The pressing need to involve all members in our democratic process means we can no longer wait for the lawyers."

Your Party has been riddled with issues ever since it was launched by the two former Labour MPs in July.

After resigning from Labour, Ms Sultana announced she was setting up the party with Mr Corbyn, only for the for the MP for Islington North to insist talks were “ongoing”.

There was then confusion over the new group's name. Ms Sultana declared it would not be called Your Party, but Mr Corbyn later hinted it might if voted for by members.

Following their disagreement over the membership email, Ms Sultana accused her co-founder of overseeing a "sexist boys club".

In reference to the party’s rocky start, Ms Sultana compared herself and Mr Corbyn to Liam and Noel Gallagher, insisting “the show is back on the road”.

“If they can do it, of course me and Jeremy can,” she added.

The Green Party has taken advantage of the high-profile disagreements and welcomed in a growing number of Left-wing voters disillusioned with Labour.

In the last month, Zack Polanski's party has seen its membership double to more than 150,000.

Your Party members are expected to vote on the party's official name before a founding conference is held in Liverpool on November 29 and 30.

But draft-founding documents suggest the party could be left without a leader or co-leader until the end of March, with a ballot only expected after the conference.

MOU are expected to issue a statement on Monday.