The results provided Labour with a boost even after a U-turn on the party’s pledge to spend £28 billion on green projects and the anti-semitism row that forced it to drop Azhar Ali, who had been standing for the party in the upcoming Rochdale by-election.

It overturned majorities of 11,220 and 18,540 in Kingswood and Wellingborough respectively in its second-ever largest swing from the Tories, though given low turnouts its actual vote fell in Kingswood and rose only marginally in Wellingborough.

Congratulating the new MPs, a spokesman for Momentum said: “It’s clear — after 14 years of austerity and privatisation, the public are crying out for real change from the Tories.

Both contests were seen as two-horse races between Labour and the Tories.

The right-wing Reform party’s deputy leader Ben Habib won 13 per cent in the heavily pro-Leave constituency of Wellingborough.