Labor has won the Chester by-election, the first public vote since Boris Johnson and Liz Truss were kicked out of No 10.
Samantha Dixon retained her party’s seat with 17,309 votes, a 61% share and almost 11,000 more than the Conservative candidate.
Labor was expected to win, but the margin was wider than in 2019, when its majority was 6,164, or just under 50%.
It represents a swing of 13.8% from the Conservatives to Labour, the sixth biggest among parties in a by-election since 1945, and more than Wakefield’s 12.7% in June.
It is also the worst result for the Tories in Chester since 1832, with candidate Liz Wardlaw getting 6,335 votes, or 22.4%.
Latest politics: Labor retain Chester by an increased margin of 11,000
Ms Dixon told Sky News the result was a “resounding mandate” for Labour, and in her victory speech said the Tories were “on borrowed time and people want change”.
Sky’s chief political correspondent Jon Craig described it as a “crushing defeat” for the Tories and “ominous” for the party’s chances at the next election.
However, he said it would be harsh to blame the new chief minister Rishi Sunak personally for the result.
Analysis: Not just a bad result, but a disaster
Image: Voter turnout was 41.2 percent, Chester election officials said
It comes after major disappointment for the Tories in two summer by-elections which saw Labor sweep Wakefield and the Lib Dems claim historic victories in Tiverton and Honiton.
Chester’s contest was triggered by the resignation of Labor MP Chris Matheson, who was suspended in October after two allegations of sexual misconduct by a former staff member were upheld.
The result follows a drop in opinion polls for the Conservatives after a series of reshuffles in their front ranks.
Image: The by-election is the first since Rishi Sunak became Prime Minister
The party saw a small bounce in its numbers after Rishi Sunak entered Downing Street last month – the third Tory leader this year – but the Tories are still regularly polling behind Sir Keir Starmer’s Labor Party.
This is the first of two by-elections this month, with another on December 15 in Stretford and Urmston in Greater Manchester.
This vote was called after Labour’s former shadow education secretary, Kate Green, announced she was standing down as deputy mayor of Manchester.