Hannah Spencer, a 34-year-old plumber and Green Party member, achieved a stunning and historic victory in the Gorton and Denton by-election, overturning Labour's formidable 13,000 majority. Her win, securing 14,980 votes and a 4,402 majority, marked a seismic shift in what was once considered one of Labour's safest seats, pushing Labour into third place behind Reform UK's Matt Goodwin, who came second. This triumph makes Ms. Spencer the Green Party's fifth Member of Parliament and their first in Greater Manchester and the North West, breaking Labour's nearly century-long hold on the constituency since 1935.

Following her emotional victory speech, where she famously stated, "I didn't grow up wanting to be a politician. I am a plumber," Ms. Spencer embarked on a busy whistle-stop tour of her new constituency. Her day included holding her first surgery at Longsight Art Space with Green Party leader Zack Polanski, visiting Sue's Chinese takeaway in Gorton for chips and curry sauce, attending a press conference at the Crystal Suite in Belle Vue, and even a spot of karaoke. In her remarks to reporters, she expressed gratitude to her campaign team and the people of Gorton and Denton, promising to work hard to deliver for them, influence policy to improve lives, bring down the cost of living, introduce rent controls, and tackle litter and fly-tipping. She highlighted a positive campaign against what she termed the 'stale, broken, old two-party politics' of Reform UK and Labour.

Labour strategists had initially displayed misplaced optimism, with general secretary Hollie Ridley stating the contest was a "two-horse race" with Reform UK. Cabinet ministers were dispatched to reassure journalists, claiming data looked good and that Labour was executing its biggest-ever 'get out the vote' operation. This strategy was partly built on positioning Labour as the pre-eminent force against Reform UK's candidate, Matt Goodwin, and was designed to make voters believe Labour was the best chance to defeat him. However, ground reporting and betting markets told a different story, revealing widespread voter disillusionment with the government's performance and, notably, Labour's decision to block Greater Manchester mayor Andy Burnham from standing in the by-election.

The scale of Labour's defeat, with their vote share almost halving from 50.7% in 2024 to 25.4% in the by-election, plunged the party into despair. Andrew Western, Labour's political lead in the campaign, conceded defeat by 10 pm, and by 1 am, the party officially acknowledged the loss. Prime Minister Sir Keir Starmer faced immediate calls to change direction or resign, with Angela Rayner, a prominent figure on Labour's left, labeling the result a "wake-up call." Starmer, however, appeared defiant, using television appearances and a letter to MPs to attack the Greens as an "extreme" left-wing equivalent of Reform UK, claiming they could not replicate such success in a general election. This response further infuriated many Labour MPs, who felt it was tone-deaf and failed to grasp the depth of the party's unpopularity, especially among its own supporters and ethnic minority voters. Critiques from within the party, including the Mainstream Group and Unite's Sharon Graham, urged Starmer to listen to everyday people rather than "rich mates." Some MPs warned that without a significant turnaround, Starmer could face a leadership challenge after upcoming elections in May.

The Green Party's campaign, meanwhile, was lauded as a "blinder." By selecting Hannah Spencer, a local plumber, as their candidate, they successfully projected a positive message of hope and change. They actively countered Labour's attempts to portray them as "extremists" or "soft on drugs" by focusing on Spencer's relatable image as "Hannah the plumber," which was ubiquitous on billboards, social media, and streets. The party's confidence was evident, with details of Spencer's victory lap, including karaoke and marking iftar at a mosque, being shared even before polls closed. Green Party leader Zack Polanski famously declared, "we’re not here to be disappointed in Labour, we’re here to replace them."

Despite her victory, Ms. Spencer faced accusations of hypocrisy during the campaign. It emerged that she co-owned two houses in affluent postcodes worth over £1m with her former partner, Dr. Stephen Holman, and had offered tips on Mumsnet about making the most of property deals, including threatening to sell to another buyer if initial buyers were "stingy" and endorsing second homes "as an investment" – policies contrary to Green Party principles of abolishing private landlords, taxing the rich, and bringing in rent controls. Furthermore, her social media documented foreign holidays to Amsterdam, Valencia, Barcelona, New York, San Francisco, and Hungary, contradicting an environmentally-conscious stance on flying. She also faced criticism for past comments in a 2021 Mumsnet post, where she disparaged the Levenshulme district of South Manchester, calling it "hugely blighted by a mile long row of (supposedly) money laundering takeaways" and expressing relief at having moved away. A Green Party spokesperson defended Ms. Spencer, stating she is a "real life, working class, human being" and that the party does not believe people should be deprived of transport or holidays.

The by-election was also marred by allegations of corrupt voting. Reform UK and the Conservatives formally asked the elections watchdog to investigate "family voting," an illegal practice where one family member allegedly dictates how others cast their ballot. Election observers from Democracy Volunteers reported "concerningly high levels" of this, claiming 12% of observed voters were involved. Nigel Farage, leader of Reform UK, publicly claimed "cheating" and "sectarian voting" had occurred, contacting both the police and the Electoral Commission and raising concerns about postal votes in "predominantly Muslim areas." James Cleverly, the Conservatives' shadow communities secretary, echoed these concerns, citing the Democracy Volunteers report as evidence of "electoral offences." However, Manchester City Council vehemently denied any issues were reported during polling hours, criticizing Democracy Volunteers for waiting until after polls closed to make their claims. The Electoral Commission emphasized that observers should report irregularities "on the spot." Greater Manchester Police confirmed receiving Reform UK's report and are reviewing its contents.

The Gorton and Denton result represents a significant disruption to Britain's established two-party order, being the first by-election where neither Labour nor the Conservatives finished in the top two. The Conservatives suffered their worst-ever by-election result nationally, securing less than two percent of the vote and losing their deposit. This outcome, with a swing of 26.4% from Labour to the Greens, ranks among the largest by-election swings against a sitting government in recent parliamentary history. For Keir Starmer, the setback comes relatively early in his government's tenure, without the usual crises to blame, leading to intense pressure from within his party to shift leftwards, particularly concerning issues like migration policy. Ms. Spencer's election also means she will step down from her role as a councillor for Hale, Trafford, though she intends to serve residents until the local election in May, with Orla Weir slated to contest her seat.