The Labour Party appeared to concede while the Green Party was confident of a victory as counting was underway in the crucial Gorton and Denton by-election.
The party’s deputy leader, Lucy Powell, said the Greens “have managed to win that argument that they were best placed” to keep Reform UK out of the Manchester Central constituency.
Zack Polanski’s party said “things are feeling positive”, while Labour sources suggested the Greens “have been able to turn out support” in the contest, widely seen as a major test of Sir Keir Starmer’s leadership.
However, with the vote a three-way race between Reform, Labour and the Tories, it is expected to be extremely tight when results are declared from 4am.
Despite Labour having won the seat at the 2024 general election with more than 50 per cent of the vote, Sir Keir’s party is currently the third favourite amid a surge in support for Mr Polanski’s party on the left and the march of Nigel Farage’s Reform UK on the right.
If the Greens win tonight, it would be the party’s first-ever victory in a parliamentary by-election, with a party source predicting a “seismic moment” in UK politics.