Corbyn clashes with Sultana over membership portal as split emerges in new party

An extraordinary split has opened between Jeremy Corbyn and Zarah Sultana in the formation of their new leftwing party, with the former Labour leader suggesting he will take legal action over an unauthorised membership portal promoted by his co-leader.

Sultana claimed the party was being run by a “sexist boys’ club” and suggested there were deep disagreements over how to launch party membership – including with the four other MPs in Corbyn’s Independent Alliance.

The split emerged on Thursday when Sultana revealed a new membership portal on X, urging supporters to “be a part of history”. Within half an hour she celebrated “10,000 paid-up members” in a separate post and reassured her followers that the membership site was “safe and secure”, encouraging them to keep trying to sign up despite “issues due to such high traffic”.

By early afternoon, Sultana said numbers had hit 20,000, dismissing suggestions from those she classed as “rightwing bad faith actors” who said “this link is fake.”

Sultana had posted about the new portal three times before Corbyn issued an “urgent message” telling his followers on X to ignore the site and indicated “legal advice is being taken.”

“This morning, an unauthorised email was sent to all yourparty.uk supporters with details of a supposed membership portal hosted in a new domain name,” Corbyn said.

“Legal advice is being taken. That email should be ignored by all supporters. If direct debits have been set up, they should immediately be cancelled.”

The clash is the most dramatic in a series of tensions that have plagued the project since its staggered launch in July.

Sultana, who been suspended from Labour since a rebellion over the two-child benefit cap, announced unilaterally she was co-leader of a new party along with Corbyn, a move that some within the group felt was premature and potentially counterproductive.

Several hours later, the former Labour leader confirmed he was in discussions about creating the new party but avoided confirming any formal structure or leadership arrangement, giving his preference for collective decision-making.

By late July the pair had formally agreed to launch a party together, with a pledge to hold mass gatherings and a founding conference in autumn.

But divisions over control and process have resurfaced. Insiders disagreed over whether the party should operate as a member-driven organisation – with a space for grassroots debate and policy setting – or take on a tighter model built around a small group of MPs and organisers.

There have also been divisions over control of membership data and finances. It was those that burst into the open on Thursday, with Corbyn’s statement co-signed by all of the Independent Alliance MPs bar Sultana: Ayoub Khan, Adnan Hussain, Iqbal Mohamed and Shockat Adam.

That joint statement from all of the other MPs in the alliance prompted Sultana to claim she had been sidelined and excluded from key decisions.

“Neither of this week’s emails had the dual authorisation of both myself and Jeremy – which was the agreement made at the start of this process,” she said in a statement posted on X.

“After being sidelined by the MPs in today’s statement and effectively frozen out of the official accounts, I took the step of launching a membership portal so that the supporters could continue to engage and organise.”

She added: “My sole motivation has been to safeguard the grassroots involvement that is essential to building this party. Unfortunately, I have been subjected to what can only be described as a sexist boys’ club: I have been treated appallingly and excluded completely.

“They have refused to allow any other women with voting rights on the working group, blocking the gender-balanced committee that both Jeremy and I signed up to.”

Sultana also warned about power being concentrated in too few hands, intimating she was uncomfortable with the control being exerted by former Corbyn staffers from when he was leader of the opposition.

“I do not believe members will accept Karie Murphy [Corbyn’s former chief of staff] and her associates having sole financial control of members’ money and sole constitutional control of our conference. This undermines the democratic principles we agreed to uphold.”

She called on Corbyn to meet her and “make public all agreed structures, processes and decision-making protocols”, adding: “This party is more important than any one person, and we all owe it to the movement to deliver a truly democratic and socialist party. No stitch-ups, no coronations: the members must decide.”

Insiders have told the Guardian that allies of Corbyn have been asserting increasing control of the working group over financial and constitutional decisions, leaving Sultana pushing for a member-led structure. But others said Sultana has been on “wrecking manoeuvres” and “sought after nothing but power”.

An ally of the project said the row risked sending a “terrible signal to supporters still deciding if this project is serious”. It remains unclear whether the project will survive in the same form until its own founding conference in autumn.