Your Party membership 'just one-third of the Greens' after Corbyn-Sultana spat hurt recruitment

The figure is said to be short of the 100,000 to 200,000 that the party hoped would join after its launch.

Around 800,000 had previously expressed interest in joining upon the announcement of its founding - but the birth of the venture was complicated by a row between former Labour MPs Corbyn and Sultana.

The lacklustre numbers put the hard-left group behind many of their political competitors - including the Green party, whose membership has surged to round 150,000 in recent months.

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It is the latest blow to their new political group, after they announced that more than 20,000 people's data was lost following the launch of the membership portal by Ms Sultana.

Your Party said it expects the numbers to increase as more members move over from the "unauthorised" portal that the MP for Coventry South set up during a spat with Mr Corbyn 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.

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."

Ahead of a rally to announce the numbers, Mr Corbyn told Sky News: "I am excited to announce that 50,000 people have now become members of Your Party.

"This major milestone reflects what Your Party is all about: a mass, democratic movement for change. From local rallies to mass regional assemblies, people up and down the country are coming together to build this party from the ground up.

"This is just the beginning. At the end of this month, we will host our founding conference. This will be the moment that members come together to launch our mass, democratic movement for real change."