Shortly after 11.30am on Friday 30 January, in a community centre on the side of an A-road in south-east Manchester, Zack Polanski made a joke. “The Houses of Parliament,” Polanski said. “Leaky roofs, crumbling walls. I think they need a plumber.” His audience – an array of Green Party activists and local members, all there to hear who had won selection as the party’s candidate in the Gorton and Denton by-election – crumbled into giggles. The winner, Hannah Spencer, is a plumber. Four weeks later and 34-year-old has defied the odds to become the party’s fifth MP, securing a historic by-election victory in Gorton and Denton. The Green Party has contested 87 by-elections: this is the first it has won.
The race was widely viewed as too close to call: a three-way fight between the incumbent Labour Party, the Greens and Reform. It was a particularly hard-fought battle between the first and second parties, each claiming they were the true progressive option to beat Reform. Left-leaning voters were being asked to choose between two distinct versions of the British progressivism: Polanski’s Greens or Keir Starmer’s Labour.
Yet the Green Party’s victory was decisive. Spencer took 41 per cent of the vote, ahead of Reform’s Matt Goodwin with 29 per cent and Labour’s Angeliki Stogia with 25 per cent (Labour – which has been dominant in this seat for decades – saw a 25-point decrease in its vote share from the general election in 2024).
Green Party insiders told me they never thought Spencer’s victory was in question. But they did not expect it to be so conclusive. Gorton and Denton was number 127 on the party’s list of target seats. “We were confident Hannah was going to win this, but what a margin,” one Green Party source messaged, in the early hours after Spencer’s election was announced. “It shows that not only is the Green surge real, but the polls might be underestimating us. When voters believe Greens can win, they vote for us, and we do win and comfortably so.”
This was the first electoral test for Polanski since he became the party’s eco-populist leader in September 2025. The Greens’ membership has exponentially grown since then, from just over 68,000 when Polanski was first elected, to 190,000 in January. Under his leadership, the Greens have become more vocal on social justice issues, calling for drug decriminalisation and wealth taxes. The policies, reminiscent of Jeremy Corbyn’s Labour, have caused the consternation among some more traditional Green backers, who are critical of the party’s perceived neglect of the environment. Polanski’s Greens feel like a party focused on winning over voters in Britain’s urban centres, not its rural peripheries.
Spencer’s acceptance speech was light on environmental issues, instead focusing on the cost of living, billionaire backers and social justice. But to anyone who has followed the party closely since Polanski’s election, this shift was inevitable. His explicit platform of eco-populism – with its punchy slogans and bolshie communications style – was always intended to reposition the Greens as a populist force on the left.
A crucial element of the Greens’ decisive victory, however, was their ability to cut through in the Muslim community. The Muslim Vote campaign group – which assisted in the election of several of the Gaza Independents in 2024 – endorsed the party before the campaign. Speaking to the NS ahead of the vote, Fesl Reza-Khan, the co-chair of the Muslim Greens, said getting the message out to vote Green via mosques and local Islamic community centres has helped to persuade older Muslim voters who have always voted Labour.
This was a particularly toxic campaign. In the final week before polling, the Greens were criticised for some of the campaign material used in Gorton and Denton, most recently their publication of a campaign video in Urdu that featured a picture of Keir Starmer with the Indian prime minister Narendra Modi. When asked by the New Statesman about the videos, a Green Party source pointed out that Labour had used similar tactics in Batley and Spen in 2021, when they printed leaflets showing Boris Johnson and Modi shaking hands.
The Green Party sees itself as the main left-wing opponent to Starmer’s Labour. At a press conference in the constituency on Friday morning, Polanski described Spencer’s win as a “seismic victory” adding, “Labour’s electoral stranglehold is over.” Facing questions from the press pack, Spencer said: “I was here to replace Labour in Gorton and Denton and that’s what I’ve done.”
Polanski has previously spoken about potential defections to the Greens from the Labour benches (in an interview with the NS last May, he said he would roll out the red carpet for Clive Lewis), and several former Labour figures including the former North of Tyne mayor, Jamie Driscoll, and Labour National Executive Committee member, Mish Rahman, have recently joined.
After Robert Jenrick defected from the Conservative Party to Reform UK, Nigel Farage put a deadline of the 7 May elections for MPs to switch to his party – would Polanski do the same? Polanski told the NS: “It’s just not my priority right now.” But he left the door open for potential future joiners: “Any MP who shares our values, I’m always open to those conversations.”
[Further reading: The Greens now have a very, very high ceiling]
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Subscribe here to commentLabour seems to be heading in the same direction as the Tories – into oblivion. And who is to blame? Starmer of course. He, presumably taking the advice of his advisors, rapidly jettisoned the left wing policies he had embraced to get elected as leader, and has since shown that he lacks any political philosophy at all. While Starmer remains as leader, and lacking all leadership qualities, Labour will continue to decline. And there is no one in the current cabinet, as far as one can see, who would do any better. The next general election is going to be a complete mess and the only way to save it is to introduce proportional representation as soon as possible.
A smashing victory for the Greens. Truly impressive result