By Louise Thompson, Senior Lecturer in Politics, University of Manchester
The byelection in Gorton and Denton has been huge for the Green Party of England and Wales. Hannah Spencer pushed Reform’s Matt Goodwin into second place and Labour into third — taking nearly 41% of the vote, a 28-point increase on the same constituency at the 2024 general election. The Greens had never won a byelection before. Unlike Reform UK in Runcorn and Helsby, the Greens didn’t just edge this victory — they dominated it.
The win has given party leader Zack Polanski the confidence that voters now see the Greens as a viable alternative to Labour, even in former strongholds. He announced to supporters: “this is what replacing Labour looks like.”
Over the past few years the Greens have professionalised significantly. At the 2024 general election they quadrupled their number of MPs and finished second in 40 constituencies. Under Polanski’s leadership they have developed a more populist edge, focusing on the cost of living and moving away from being “just” a climate party — a shift from the era when Caroline Lucas carried the weight of the party’s national profile almost entirely alone. They have also had a more visible media presence and started taking their communications strategy more seriously.
What Five MPs Means
Spencer’s win increases the Green parliamentary group to five MPs. In a 650-member House of Commons that doesn’t sound like much. The Greens certainly aren’t large enough to swing votes, and there are still over twice as many independent MPs as there are Greens.
But the win gives the party breathing space. It’s a tough job being a small party in the Commons, and the existing group of four Green MPs have shared a heavy burden of responsibilities since their arrival in 2024. Spencer will take on policy portfolio responsibilities, and a bigger team allows the party to insert Green voices into more conversations — through committee places scrutinising legislation, catching the Speaker’s eye during high-profile statements and question times, or holding backbench debates on local issues.
The approach matters. While Nigel Farage regularly berates Starmer in the Commons, the Greens tend to take a more balanced, policy-focused approach, regularly contributing on committees. This is helped by Polanski’s position as a leader who sits outside the Commons as a member of the London Assembly, delegating government scrutiny to Chowns and colleagues while taking broader political commentary directly to the press.
The Battle Ahead
When the next general election draws closer, the Greens will want to capitalise on their Manchester success and continue professionalising as a national party. They are also likely to face more hostility at Westminster. Labour is now fighting a war on two fronts. The party’s embarrassing third-place result — which Keir Starmer called “very disappointing” — will have hammered this home. We can expect to see more attacks on the Greens, including in the chamber.
Until now the Prime Minister has focused much more consistent attention on discrediting Reform. Now he needs to worry about Polanski and the Greens, directing focus toward winning back Labour voters who see the Greens as the stronger party of the left. We had a glimpse of this in January, when North Herefordshire’s Ellie Chowns used her occasional opportunity to question the PM about water pollution, and Starmer turned it into a partisan attack on Polanski’s comments about NATO.
For anyone watching from Brighton and Hove — a city with deep Green Party roots and the experience of being the only Green-led council in the country — the national trajectory feels familiar. The Greens have long understood that building from local government upward is the path to credibility. The pattern playing out in Manchester mirrors what Brighton saw years ago: voters choosing the Greens not as a protest but as a genuine governing alternative.
That local dimension matters nationally too. Labour’s approach to local democracy — including plans to force councils away from the committee system — has created friction with Green councillors who argue it concentrates power and silences opposition voices. Issues like housing, where Brighton’s Greens have clashed with Labour over tenant protections and renter rights, provide the kind of bread-and-butter policy ground that wins byelections.
Spencer told the press the party can now “win anywhere,” and Polanski predicted a “tidal wave” of Green MPs at the next election. To deliver that, they need to maintain this week’s momentum — keeping hold of the former Labour voters who chose them in Gorton and Denton. It will be difficult to carry out the same intensive campaign strategy on a national level, but having more party members than ever before will help.
The bigger question is whether a first-past-the-post system built for two parties can accommodate a serious third and fourth force. The case for electoral reform — long championed by the Greens — grows stronger each time a party wins 41% in a byelection but remains a fringe presence in Parliament. For now, the Greens are proving they can win under the existing rules. Whether those rules change may ultimately determine how far this momentum carries.
