In the ever-shifting landscape of British politics, the launch of a new left-wing party by Jeremy Corbyn and Zarah Sultana was supposed to signal a bold beginning. Instead, a dramatic and public falling out between the two prominent figures has thrown the nascent movement into turmoil, while unexpectedly handing a boost to the Green Party, which has seen a surge in new members amid the chaos.
The drama erupted on September 18, 2025, when Zarah Sultana, the MP for Coventry South, accused former Labour leader Jeremy Corbyn of presiding over a "sexist boys' club" and claimed she had been sidelined by other members of the party's working group. Sultana's explosive charge came just as she launched an online membership portal for the yet-to-be-officially-named party, currently referred to as "Your Party." She encouraged supporters to join as paid-up members, boasting on social media that more than 20,000 people had already signed up. The portal offered full membership at £5 a month or £55 a year, and Sultana insisted it was "a safe, secure, legitimate portal for the party," with funds being held by a company set up to safeguard the money until the founding conference in November.
However, Corbyn and his allies were quick to distance themselves from the initiative. In a statement issued the same day and signed by four independent MPs involved in founding the party—Ayoub Khan, Adnan Hussain, Iqbal Mohamed, and Shockat Adam, but notably not Sultana—Corbyn declared the emails and the portal "unauthorised" and urged supporters to cancel any direct debits immediately. According to the BBC, Corbyn stated, "The emails were 'unauthorised' and should be ignored, while any direct debits set up should be 'immediately cancelled.'" The party then referred the matter to the UK's Information Commissioner's Office (ICO), which confirmed it was assessing the information provided.
This public dispute quickly became a spectacle, with Andrew Fisher, Corbyn's former policy director, lamenting the situation on BBC Radio 4's World at One: "If they can't get their act together between them, it doesn't give people a lot of faith that the vehicle can get off the ground." Fisher warned that the infighting might push potential supporters towards the Green Party, which he described as a stable alternative for left-leaning voters. "I suspect a lot of people... have probably looked at this and gone, 'Nope, not worth the bother. I might join the Greens with Zack Polanski, who is an articulate leader in a stable party that is making left-wing arguments.' And maybe that's the vehicle that will take off as a result of this."
The numbers appear to support Fisher's assessment. In the 24 hours following the row, the Green Party reported that nearly 1,400 new members had joined, pushing its membership above 75,000—a more than 10% increase since Zack Polanski's election as leader earlier in September. According to The Guardian, Polanski welcomed the growth but was cautious about future cooperation with Corbyn and Sultana. "My door is always open for conversations with Jeremy and Zarah, two people committed to making our country fairer who I really respect. But today I’m focused on growing the movement within the Green Party," Polanski said.
For the new party, the dispute was not just about membership logistics or finances. At its heart, it exposed deeper rifts over leadership and inclusivity. Sultana accused Corbyn’s allies of excluding her from decision-making, describing the party as a "sexist boys' club." In her own statement, she insisted that the membership portal was launched "in line with the road map set out to members" and was intended to allow supporters to "continue to engage and organise." She maintained that all funds were being properly safeguarded until the party's founding conference, scheduled for November.
Corbyn, for his part, strongly rejected Sultana’s claims of exclusion. He insisted that she "had not been excluded from any discussions" and that the process remained "rooted in inclusivity and mutual respect." Allies of Corbyn also denied that Sultana had been shut out from consultations, stating that no decision had been made by the working group on data and finances. Nevertheless, the perception of a leadership struggle persisted, with some within the party suspecting that Sultana was preparing to "go it alone" or even mount a leadership bid before the party had been officially founded.
The dispute also highlighted uncertainty over the party’s identity. Even the name remains up in the air. Sultana has insisted the party should not be called "Your Party"—her preference is for "The Left Party"—while Corbyn has hinted that the provisional name could stick. The final decision on the name is set to be put to a vote by supporters at the founding conference.
Despite the bumpy start, the appetite for a new left-wing alternative is clear. Since its launch in July, the party claims more than 750,000 people have signed up to get involved in some capacity. Yet, as Fisher and others have pointed out, enthusiasm alone may not be enough if the party’s leadership cannot present a united front. The Green Party, meanwhile, is capitalizing on the moment. As Polanski told the BBC, "The Green Party just really have momentum at the moment, and we don't have time to waste. I know a lot of people in this country right now want to see a party ready to challenge Reform and challenge this deeply unpopular Labour government, and that's exactly what I intend to do."
Insiders close to the new movement told The Guardian that efforts were underway to de-escalate tensions, with "serious attempts" being made to identify a way forward. "Emotions were running high, but there is an appetite for de-escalation on both sides," one source said. As of Friday, September 19, 2025, both camps were reportedly working to calm the mood and find a realistic path ahead, with possible news expected next week.
While the new party’s future remains uncertain, the events of the past week have underscored the challenges of building a political movement from scratch—especially when personalities and principles collide in public view. For now, the Green Party is the clear beneficiary, but the coming weeks will reveal whether Corbyn and Sultana can mend fences or if their project is doomed before it even begins.
