Labour has won another seat from the Tories as Rishi Sunak suffered more by-election misery.
The party overturned a majority of 11,220 to emerge triumphant in Kingswood.
The seat was previously held by former energy minister Chris Skidmore, who quit as an MP last month in protest at the prime minister watering down his green commitments.
Labour’s Damien Egan received 11,176 votes, giving him a majority of 2,501 over Tory candidate Sam Bromiley. It represents a 16.4% swing from Conservative to Labour.
Since becoming prime minister in October 2022, the Tories have lost by-elections in Selby and Ainsty, Somerton and Frome, Mid Bedfordshire and Tamworth, while winning just one in Uxbridge and South Ruislip.
The party was also on course to lose the by-election in Wellingborough, which was due to be announced soon after the Kingswood result.
The result is also a further blow to the prime minister after it was confirmed the UK has gone into recession – despite his promise to grow the economy.
A breakdown of the result also suggested the Tory vote being split with Reform UK. Bromiley received 8,675 votes, 34.8% of the total, while Reform UK candidate Rupert Lowe managed his party’s best result so far winning 10.4% of the vote.
Keir Starmer, leader of the Labour Party, said: “This is a fantastic result in Kingswood that shows people are ready to put their trust in a Labour government.
“By winning in this Tory stronghold, we can confidently say that Labour is back in the service of working people and we will work tirelessly to deliver for them.
“To those who have put their trust in us, you can be safe in the knowledge that the Labour Party will deliver on your priorities. Labour will give Britain its future back.”