Labour is celebrating a stunning double by-election triumph as the Tory vote collapsed in two previously-safe seats.
In a hammer-blow for Rishi Sunak, Keir Starmer’s party scored significant victories in Kingswood and Wellingborough.
The results will pile even more pressure on the prime minister with the general election just months away.
In Kingswood, Labour’s Damien Egan overturned a Tory majority of 11,220 to become the seat’s new MP.
And in Wellingborough, Gen Kitchen was elected on a massive 28.5% swing from the Conservatives to Labour - the second biggest on record.
Tory MPs will also be worried by the performance of the right-wing Reform party, which won 10% of the vote in Kingswood and 13% in Wellingborough.
Keir Starmer said: “These are fantastic results in Kingswood and Wellingborough that show people want change and are ready to put their faith in a changed Labour Party to deliver it.
“By winning in these Tory strongholds, we can confidently say that Labour is back in the service of working people and we will work tirelessly to deliver for them.
“The Tories have failed. Rishi’s recession proves that. That’s why we’ve seen so many former Conservative voters switching directly to this changed Labour Party.
“Those who gave us their trust in Kingswood and Wellingborough, and those considering doing so, can be safe in the knowledge that we will spend every day working to get Britain’s future back.”
Elections expert Luke Tryl of the More in Common think-tank described the result in Wellingborough as an “absolute Tory meltdown”.
The Kingswood by-election was called following the resignation of former energy minister Chris Skidmore in protest at Sunak watering down his green policies.
The by-election in Wellingborough was triggered after long-serving Tory MP Peter Bone was dumped by his voters in a recall petition.
He lost the Conservative whip last October after he was found to have bullied and sexually harassed a member of his staff.
After being suspended from the Commons for six weeks, enough voters in his seat supported the petition calling for his removal as their MP.
The two results mean Sunak has now lost six by-elections in previously-Tory seats since becoming prime minister in October, 2022. The others were in Selby and Ainsty, Somerton and Frome, Tamworth and Mid-Bedfordshire.
In all, the Tories have lost 10 seats in by-elections this parliament, the most by any government since the 1960s.
Pollster Michael Thrasher told Sky News: “With so little time left, that general election clock is ticking away, [the Tories] are running out of time to turn this around.
“They really are on course to lose their overall majority [and] they really are on course to be overtaken by Labour as the largest party.”
The results are also a huge boost for Starmer after one of his most difficult weeks since becoming Labour leader nearly four years ago.
He has faced criticism for dumping Labour’s pledge to spend £28 billion on green energy projects, as well as for the time it took for Labour to withdraw support for Azhar Ali, the party’s candidate in the upcoming Rochdale by-election, over anti-Israel comments.