The Green Party have won the Gorton and Denton by-election.
Hannah Spencer has become the party's fifth MP in parliament, after beating Reform UK, who finished second, and Labour, who came third, to the seat.
The Greens, who had earlier said they were "very confident of a win", received 14,980 votes to claim a majority of more than 4,400 votes. Reform picked up 10,578 votes, while Labour received 9,364 votes.
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It is the Greens' first-ever victory in a parliamentary by-election, and the first time the party has won a seat in the north of England.
Speaking to Sky News, Ms Spencer said she "knew it was always possible" for the Greens to win in Gorton and Denton.
"There is an appetite here for change," the 34-year-old said.
"There are people across this constituency and much further beyond who are rejecting the old political parties and who are coming together to fight for something better, but who are doing it positively and in a really hopeful way."
Green Party leader Zack Polanski criticised Labour for what he called "a shameful, dirty campaign - spreading lies about Green policies and even faking a tactical voting website".
"They knew they couldn't win, but they risked splitting the vote and letting Reform in," he said.
"People everywhere will now know that voting Green is the way to defeat Reform."
The turnout for the vote was 47.6% of the electorate, slightly lower than the 47.8% at the 2024 general election.
In a post on X, Nigel Farage claimed the by-election, which had been triggered by the resignation of former Labour MP Andrew Gwynne on health grounds, was "a victory for sectarian voting and cheating".
It follows concerns raised by election observer group Democracy Volunteers. The organisation said it witnessed record numbers of illegal "family voting".
Family voting is where two voters either confer, collude or direct each other on voting, which is illegal under the 2023 Ballot Secrecy Act.
John Ault, director of Democracy Volunteers, said: "Today we have seen concerningly high levels of family voting in Gorton and Denton.
"Based on our assessment of today's observations, we have seen the highest levels of family voting at any election in our 10-year history of observing elections in the UK."
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Home Secretary Shabana Mahmood's immigration policies have been cited by some in Labour as a key reason for the party's loss of a seat it has historically held, which was also its 38th safest seat in 2024.
Reacting to the loss, Transport Secretary Heidi Alexander told Sky News it has been a "difficult and deeply disappointing night" - but insisted: "I don't think we should over-interpret this result."
The cabinet minister added that it's "not unusual for governing parties to lose mid-term by-elections".
She said: "There is no direct read across from what happens in a by-election to what happens in a subsequent general election.
"And just because people in Gorton and Denton voted for a Green MP, it doesn't automatically follow that they want Zack Polanski to be their prime minister, or for that matter, Nigel Farage, which, I think, is the greater threat across the country.
"We will, of course, reflect carefully on that result," she added.
(c) Sky News 2026: Green Party wins Gorton and Denton by-election
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