Corbyn Holding The Dynamite: Could ‘Your Party’ Shatter The Two-Party System?

Jeremy Corbyn and Zarah Sultana have launched a new left‑wing party, temporarily called “Your Party”, with more than 200,000 people signed up in the first 24 hours. That's more than 60% of the flagging 'Labour' membership under Starmer - estimated at just over 300,000 in February.

With 'Labour' said to be losing a member every 10 minutes back then, membership should be down another 25,000 by now - and likely to fall further after Corbyn's announcement.

The new party promises wealth redistribution, public ownership of utilities, rent controls, universal basic income pilots and an end to arms sales. They say the party will be decided by members at an autumn conference. Many warn the split will fracture the left, but the founders insist this is no ordinary venture, given Corbyn’s huge profile and grassroots base.

Corbyn and Sultana unveiled their plans in a broadcast from Islington. They spoke in simple language. They stressed the party will grow from unions, community groups and local campaigns. Sultana said supporters have waited for a bold offer since Labour moved to the centre under Keir Starmer. Corbyn argued that former mainstream allies have betrayed core values and left voters without a home.

Their new home is to be a new kind of political party - find out more and sign up at yourparty.uk

From the launch statement

The launch arrived amid reports that the Conservatives risk losing ground to Reform UK, which now tops some polls. YouGov finds Reform winning 28% against the Conservatives’ 24% and Labour’s 30% nationally. Experts warn that a strong showing by Corbyn’s party could tip marginals, ending the old two‑party system. Professor Robert Ford notes that if “Your Party” takes even 10% of the vote, it could cost Labour dozens of seats and let Reform win more Tory‑held areas.

Critics accuse Corbyn of splitting the left at a time when the right already benefits from fractured centre‑right votes. They point to the “split‑the‑left” theory, where multiple progressive options hurt the movement more than the main opponents.

Supporters say this is different, as Corbyn has never had as broad a following. They compare it to Spain’s Podemos and France’s La France Insoumise, which grew when their main left parties drifted right - and both of which have reshaped the political landscape in their respective countries.

Labour insiders play down the threat, noting Corbyn lost two general elections as leader. They say Starmer can reclaim voters with moderate policies and a focus on growth.

However, centrist opponents argue the strategy is clearly failing, pointing to Labour’s slump in the polls as evidence that mimicking Tory policies and offering little vision has left the party in a policy vacuum. Meanwhile, Reform UK’s leader has called Corbyn “a threat to national security” and warned that Labour and the left now face defeat on both flanks.

The story is unfolding against a backdrop of rising living costs and public service cuts. Grassroots activists welcome the new party as a long‑overdue home for progressive hopes. Trade unions express cautious support, though none have formally backed it. If “Your Party” endures, it could rewrite British politics.

What the right see as chaos, the founders view as opportunity. For many on the left, this may be the clearest path to real change since the 1970s, when grassroots movements last reshaped British politics from outside the mainstream parties.

With both major parties facing deep distrust for the first time in modern political memory, the old system of Tory–Labour dominance appears to be cracking. Jeremy Corbyn, still one of the most recognisable figures on the British left, may now be holding the dynamite that could finally blow it wide open.

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References:

Robert Ford, “No fear or favours: how Corbyn and Sultana’s party could blow up British politics,” The Guardian, 24 July 2025. https://www.theguardian.com/politics/2025/jul/24/no-fear-or-favours-how-corbyn-and-sultanas-party-could-blow-up-british-politics

Jim Pickard, “Jeremy Corbyn and Zarah Sultana launch new leftwing party,” Financial Times, 24 July 2025. https://www.ft.com/content/a40177c5-4cfb-4a89-b06b-62d822b645c9

Sky News Staff, “Starmer ‘would be foolish’ to ignore threat posed by Corbyn’s new left-wing party,” Sky News, 24 July 2025. https://news.sky.com/story/starmer-would-be-foolish-not-to-recognise-the-threat-posed-by-a-left-wing-corbyn-party-13392478

Ben Smoke, “Reform UK overtakes Tories in latest YouGov poll,” The Independent, 22 July 2025. https://www.independent.co.uk/news/uk/politics/reform-uk-poll-tories-yougov-b2791749.html

Joe Twyman, “Polling analysis: Could Corbyn’s ‘Your Party’ change the face of British politics?” More in Common UK, 24 July 2025. https://www.moreincommon.org.uk/blog/your-party-polling-analysis

Alone Readers Staff, “Zarah Sultana and Jeremy Corbyn launch new left-wing political party in the UK,” Alone Readers, 24 July 2025. https://www.alonereaders.com/article/details/3166/zarah-sultana-and-jeremy-corbyn-launch-new-left-wing-political-party-in-the-uk

Prospect Staff, “Could Corbyn lead a new left?” Prospect Magazine, July 2025. https://www.prospectmagazine.co.uk/politics/the-insider/70419/could-corbyn-lead-a-new-left

The Times Comment Team, “What Corbyn’s new party means for Labour’s future,” The Times, 24 July 2025. https://www.thetimes.co.uk/article/what-jeremy-corbyn-new-party-means-labour-83sdgsz32