Politics
The Green surge is coming for Keir Starmer
The Gorton and Denton by-election is historic by any measure.
The result marks the first time that the Green Party of England and Wales, which has existed in one form or another since 1973, has won a parliamentary by-election.
In fact, the Green vote share (40.7%) was four times larger than their previous best by-election performance (Somerton and Frome in 2023). Less than one year ago in Runcorn and Helsby, the first by-election this parliament (and pre-Polanski), the party polled at 7.0%, placing fourth.
Historically, parties returned with landslide majorities have proved resilient in the initial by-elections of a new parliament. Not so this government. And the nature of Labour’s recent routings has been remarkable. The result in Gorton and Denton means that the first two by-elections of the parliament have been won by Reform UK and the Greens – parties beyond the established mould of the British party system. There is no obvious precedent for such a pronounced anti-incumbent and anti-establishment turn in the electorate. The mould is breaking.
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In Gorton and Denton, the Greens (40.7%) and Reform candidate Matt Goodwin (28.7%) placed first and second – together accounting for 69.4% of the vote. The last time Labour finished third in a by-election it was defending was in Mitcham and Morden in 1982.
It also should be noted that the Conservative candidate in Gorton and Denton won just 706 votes (1.9%); this, the party’s worst-ever performance at a parliamentary by-election, has cost Kemi Badenoch’s party its £500 deposit.
The deeper one delves, the more history appears to have been made.
The contest represents the first by-election in Great Britain since the 1945 Combined Scottish Universities election in which neither of the two best-performing candidates came from the Conservative Party, Labour, or Liberal Democrats (excluding the Rochdale by-election in 2024, which was fought under highly unusual circumstances).
Hannah Spencer, new Green MP for Gorton and Denton, is the first of her party to win a seat in the North of England. Spencer’s election means that, after nearly 100 years of continuous representation, the Gorton area of Manchester will not have a Labour MP. The old constituency of Manchester Gorton was previously one of Labour’s safest seats in the country.
Gorton and Denton, the Green Party’s fifth-ever parliamentary seat, was one of only 70 seats nationwide where Labour won more than 50% of the vote share in 2024. Its 13,413-vote majority made it Labour’s 38th safest seat. The turnout on Thursday stood at 47.5% – just 0.3% below the 47.8% recorded at the general election.
Spencer overturned the sixth-largest Labour majority to fall at a by-election since the Second World War.
The Gorton and Denton result is the first time since Rochester and Strood in 2014 (when Ukip and Mark Reckless displaced the Conservatives) that an ideological rival has taken a seat from the governing party in a by-election. That contest followed the more symbolic Clacton by-election in which Douglas Carswell triumphed at his former party’s expense.
Ukip’s de facto successors, Reform UK and the Brexit Party, posed a considerable if uneven threat to the Conservatives from 2019 to 2024. But it failed to steal any seats from the Tory government during its tenure. After coming close as the Brexit Party in the 2019 Peterborough by-election, Reform did not secure over 10% of the vote again until February 2024 (Wellingborough).
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Hopefully that is suitable historical context to establish the significance of the Green victory in Gorton and Denton.
The result underlines that the Green threat to Labour and Keir Starmer, the subject of some speculation in recent months, has materialised. The Green Party has announced itself as a clear, present and probably existential threat to its rival on the left.
Sometimes by-elections really matter. Orpington. Hamilton. Eastbourne. Glasgow East. Clacton. North Shropshire. Add Gorton and Denton to that list.
For Labour, the contest is unquestionably a calamity – the worst by-election result in the party’s recent history. Labour finished third with a quarter of the vote in what it had insisted was a two-horse race between itself and Reform. The party demonstrated that it was not best positioned to defeat Reform UK in a seat it has held for decades with overwhelming majorities. On current trends, the 57% of current Green supporters who say they would hold their nose and vote tactically for Keir Starmer’s party in a fight between Labour and Reform UK will be staying put.
There is a clear echo of the Caerphilly contest, a Senedd Cymru by-election, which took place in October 2025. In both cases, Labour landed in third place behind Reform and an ascendant progressive party.
The signal these elections send is that Labour is a poor option for progressives concerned about the forward march of Faragism. This psychological watershed, of course, has similarly significant implications for idealistic progressives who have hitherto feared “wasting” their vote with the Greens.
The simplest summary of the by-election from Starmer’s perspective is that things are bad and getting worse. The result will compound the turmoil that follows May’s elections, surely shortening the prime minister’s stay of execution.
It is pertinent that Starmer placed himself at the centre of the by-election campaign with his decision to block Andy Burnham, Labour’s best bet, from standing. The prime minister’s blocking manoeuvre reflected a lack of guile and foresight – a level of political myopia that only the narrowest evaluation of one’s self-interest can produce. Even Spencer, the Green candidate, conceded that Burnham is “very popular here” and that “people really respect him”.
Starmer is discovering, as Rishi Sunak once did, that the arrival of rock bottom merely masks further plumbable depths. Labour’s decline, like the Green Party’s rise, is unreasonably well-advanced.
As such, if the Gorton and Denton by-election reflects the state of Labour under Starmer, it is equally a testament to the transformation of the Green Party under Zack Polanski’s leadership.
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I recognised that the 2025 Green leadership election was a “turning point” for the party. The Greens appeared on the cusp of unlocking their potential as a populist insurgent on Labour’s left flank. That potential is now being fully explored.
Polanski has learnt from the Faragist right about how to cut through, organise a political narrative and tell stories to a disillusioned public. “Eco-populism”, simply put, has brought a strategy certainty and self-confidence to the Greens. It has also expanded the party’s appeal beyond a handful of target seats.
Gorton and Denton is, in many respects, a different kind of seat from the Green Party’s current collection.
Adam Ramsay (Waveney Valley) and Ellie Chowns (North Herefordshire), who stood against Polanski in 2025 on a minimalist ticket, routed longstanding Conservative strongholds at the 2024 general election. Ramsay and Chowns owe their place in parliament to the party’s inroads in rural, Tory-facing seats. Meanwhile, Brighton Pavilion, a historic Green stronghold now held by Siân Berry, and Bristol Central (Carla Denyer) are younger, generally irreligious urban seats – natural hotbeds for progressive politics. In these constituencies, over 80% of voters supported remaining in the European Union (EU) at the 2016 Brexit referendum.
The Green Party’s electoral strategy pre-2024 also spanned years of grassroots activism and progression at the local government level. Before Ramsay prevailed in Waveney Valley, the Greens secured the Mid Suffolk council at the 2023 local elections. The party narrowly missed out on an overall majority on Bristol City Council in the 2024 local elections. The Ramsay-Denyer strategy bore fruit, to the surprise of some commentators, at the 2024 general election. For the Green Party, winning four seats under first past the post represented a serious breakthrough and the possibility of sustained political relevance.
But this victory in Gorton and Denton would have been unthinkable under the Denyer-Ramsay co-leadership or a hypothetical Ramsay-Chowns ticket.
Gorton and Denton is a mostly urban, ethnically diverse constituency with high levels of economic deprivation. An estimated 50% of voters in Gorton Denton supported leaving the EU in the 2016 Brexit referendum. The Greens and Spencer surged from third to first place over a relatively short campaign. In particular, the success of the Green Party in mobilising the constituency’s Muslim population should alarm Labour MPs.
The Greens have broken new ground with the scale, nature and symbolic meaning of their victory in Gorton and Denton.
Polanski has succeeded, in part, by responding to his party’s obvious political incentives. The GPEW and its sister parties finished second place in 40 constituencies at the 2024 general election; in all but one of these 40 seats, the Greens finished second to Labour. The party effectively exhausted the electoral potential of its “Countryfile conservative” strategy after securing breakthroughs in Waveney Valley and North Herefordshire.
Spencer, a former plumber who joined the Greens in 2022 because she was “so angry at the gap between the super-rich and all the rest of us getting bigger”, could prove a real asset to the party and Polanski in parliament. In her victory speech, she celebrated the defeat of “the parties of billionaire donors”. This allusion to the “pure people”-“corrupt elite” binary suggests Polanski has secured a parliamentary bridgehead for his eco-populism.
Green surges have been snuffed out before, of course: following the 1989 European Parliament elections (when the party won 14% of the vote) and ahead of the 2015 general election. But Polanski’s success in carving out a foothold for the Greens in an increasingly crowded political landscape suggests the party is not going anywhere anytime soon. Polanski will weaponise the Green victory in Gorton and Denton as proof that his party is the progressive force best equipped to thwart Farage.
The Green leader’s strategy has attracted sizeable media interest because it aligns with the moment: he has cast himself as an insurgent challenging establishment arguments. But social media clicks can only get a party leader so far. For insurgent parties, electoral success is the currency of credibility.
Gorton and Denton proves that the Green Party’s recent success is no mere mirage – the surge is real, and it is coming for Keir Starmer.
Josh Self is editor of Politics.co.uk, follow him on Bluesky here and X here.
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