The Gorton and Denton by-election, held on 26 February 2026, resulted in a historic victory for the Green Party and its candidate, Hannah Spencer.

The victory marked the first parliamentary by-election win in the Green Party’s history. Spencer also established herself as the first Green Party MP to represent a constituency in the North of England.

Spencer won 14,980 votes, representing 40.7% of the total vote share. The Reform UK candidate, Matt Goodwin, secured 28.7%, while the Labour Party candidate, Angeliki Stogia, fell to a distant third with 25.4%. The last time Labour finished third in a by-election it was defending was in Mitcham and Morden in 1982.

The result overturned a 13,413-vote Labour majority from the 2024 general election – the sixth-largest Labour majority to fall at a by-election since the Second World War.

Moreover, the contest marked 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).

Spencer’s election meant that, after nearly 100 years of continuous representation, the Gorton area of Manchester would no longer have a Labour MP.

***

The contest was triggered by the resignation of Andrew Gwynne, who served as a health minister from July 2024 to February 2025. Gwynne had the Labour whip suspended and was removed as a minister in February 2025 over his membership of a WhatsApp group which contained offensive messages. The WhatsApp group, named Trigger Me Timbers, included Labour MPs and councillors.

In a statement setting out his decision to stand down as an MP, Gwynne said he had suffered “significant ill health” and received medical advice that he should not return to parliament. The outgoing MP stated that his ill health had been “greatly exacerbated by the impact of last year’s events regarding leaked text messages”.

Gwynne’s decision to step down appeared to clear a path for Andy Burnham, the mayor of Greater Manchester, to return to parliament. Burnham, who stepped down as an MP in 2017 to contest the Greater Manchester mayoralty, responded by announcing his intention to stand as the Labour candidate. On 24 January 2026, Burnham issued a statement insisting he would “support the work of the government, not undermine it”.

At the time, Burnham was linked with a possible leadership challenger to Keir Starmer, the prime minister. The former Labour MP had previously run in the 2010 and 2015 leadership elections, and under Starmer – especially during his tenure as prime minister – Burnham had emerged as a critic. In a remarkable intervention at Labour’s annual conference in 2025, Burnham criticised a “climate of fear” in the party.

He told delegates: “To sustain a Labour government, you can’t be narrow and shallow. You’ve got to have everybody in play, everybody working together to fight the threat we’re facing. We need to be more united everybody, don’t we?”

In early 2026, the Labour Party was facing a considerable political backlash over the Peter Mandelson vetting scandal.

The Gorton and Denton by-election was arguably defined by the decision of Labour’s national executive committee (NEC) to block Burnham’s candidacy. The committee voted 8-1 to block Burnham’s candidacy; only the deputy Labour leader and Burnham ally, Lucy Powell, voted in his favour.

At the time, a Labour spokesperson said: “Andy Burnham is doing a great job as Mayor of Greater Manchester. We believe it is in the best interests of the party to avoid an unnecessary mayoral election, which would use substantial amounts of taxpayers’ money and resources that are better spent tackling the cost of living crisis.”

Burnham’s application had been supported by senior Labour figures including Powell, Angela Rayner, Ed Miliband and Sadiq Khan.

The decision to block Burnham was a boost for the Green campaign.

The Green Party, which elected “eco-populist” Zack Polanski as leader in September 2025, had won 4,810 votes (13.2%) in the 2024 general election in Gorton and Denton, placing third behind Labour (50.8%) and Reform UK (14.1%).

The Greens experienced a surge in membership following Polanski’s election. In October 2025, the party officially reached 125,000 members, surpassing both the Liberal Democrats and the Conservative Party. Opinion polls in January 2026 placed the party on as high as 17%.

Polanski’s success in late 2025 and early 2026 was attributed to his canny communications strategy and progressive disillusionment with the Labour Party under Starmer as prime minister.

Responding to the Labour NEC’s decision to block Burnham, Polanski insisted that his party was “not here to be disappointed with Labour, but to replace them.”

He added: “At the upcoming by-election in Gorton and Denton, it’s become clear that the Greens are the only progressive party capable of taking on and beating Reform. We already have activists on the ground, and we welcome any friends in Labour to support our campaign to keep Reform out of Manchester’s politics.”

The Greens subsequently selected Hannah Spencer, a plumber and local councillor, as their candidate. During the campaign, Spencer embraced the nickname “Hannah the Plumber”.

***

The result of the Gorton and Denton by-election amounted to a significant setback for Starmer’s leadership – and exposed deep fractures in Britain’s established mould of politics. Together, the Greens and Reform accounted for nearly 70% of the vote.

Symbolically, the outcome meant that Labour had been unseated in two by-elections in a row by “populist” or insurgent rivals: Reform UK in Runcorn and Helsby (May 2025) and the Greens in Gorton and Denton (February 2026).

Meanwhile, the Conservative candidate, Charlotte Cadden, finished fourth with 1.9%. This, the party’s worst-ever performance at a parliamentary by-election, cost the Conservatives their £500 deposit.

In her victory speech, Spencer celebrated the defeat of “the parties of billionaire donors”.

She declared: “I didn’t grow up wanting to be a politician. I’m a plumber. And two weeks ago, during all this, I also qualified as a plasterer. Because even in chaos, even under pressure, I get things done. I am no different to every single person here in this constituency. I work hard. That’s what we do…

“We have shown we don’t have to accept being turned against each other. We can demand better. Together. We have shown we don’t have to fight dirty to fight for change. We ran a hopeful campaign backed by thousands of volunteers and activists. We defeated the parties of billionaire donors.

“Something exciting is happening – and I invite you to be part of it. Come and join the Green party so we can spread hope and win everywhere else across the country too. Our strength will grow as more and more of us come together.”

The result of the Gorton and Denton by-election helped pile intolerable pressure on Keir Starmer.

In the wake of the May 2026 local elections and the simultaneous devolved elections to the Scottish Parliament and Senedd Cymru, renewed scrutiny was placed on the NEC’s decision to block Burnham.

Angela Rayner, the former deputy prime minister, released a statement describing the decision to block Burnham as a “mistake”.

She stated: “We must show we understand the scale of change the moment calls for – that means bringing our best players into parliament – and embracing the type of agenda that has been successful at a local level, rather than reaching back to an agenda and politics that has failed people.”

***

The May 2026 elections also prompted Josh Simons, a former junior minister, to resign his Makerfield seat. Simons’ move enabled Burnham to announce his intention to stand as a candidate; this time, he was not blocked by the NEC.

In a statement issued upon resigning, Simons said: “It is my unwavering belief that nothing short of urgent, radical, courageous reform will make a difference. That must start with a change in leadership.

“Today, I am putting the people I represent and the country I love first and will be resigning as MP for Makerfield. I am standing aside so that Andy Burnham can return to his home, fight to re-enter parliament, and if elected, drive the change our country is crying out for.”

On 4 June, Burnham confirmed that he would seek to enter any future Labour leadership contest should he win the Makerfield by-election. The Greater Manchester mayor argued that “Wes Streeting seems to have launched a leadership contest, so if that is running I would seek to join it.”

Streeting resigned as health secretary on 14 May and declared he had lost confidence in Starmer as prime minister.

Voters in Makerfield went to the polls on 18 June in what was arguably the most consequential by-election in a generation.