David Williams, chair of the Uxbridge and South Ruislip Constituency Labour Party (CLP), wrote in a tweet: "I have resigned as chair of Uxbridge and South Ruislip CLP. I am also resigning my membership of the Labour Party.

"Politics needs to have principles or we end up with people like Boris Johnson and Liz Truss running the country, Jeremy Corbyn gave a huge boost to the Labour Party."

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It comes after the Tories narrowly held off Labour in the seat at a crunch by-election, which was triggered by the resignation of former prime minister Boris Johnson.

The swing was 6.7 from Conservative to Labour - but not enough to change the party in charge.

However, the Tories' majority has been heavily reduced - from 7,000 to just under 500.

Responding to Mr Williams' statement, a Labour source said: "This is the closest we've ever run the Tories in Uxbridge and South Ruislip."

And NEC member Abdi Duale sarcastically tweeted: "Famously Jeremy Corbyn won Uxbridge in 2017 and 2019."

Labour had been expected to win the west London seat, with candidate Danny Beales holding an eight-point lead in the polls over his Conservative opponent ahead of the vote closing.

The result is being blamed by both sides on the expansion of London's Ultra-low Emission Zone (ULEZ), being championed by Labour mayor Sadiq Khan.

The controversial policy aims to tackle air pollution and congestion by charging cars that don't meet emission standards £12.50 a day to drive on central London roads.

Mr Khan wants to expand the zone to the borders of the capital, but he's been met with fierce opposition.

The new Tory MP for the area, Steve Tuckwell, who had declared the contest a "referendum on ULEZ", said Mr Khan had "lost Labour this election" as he called for him to change course.

Senior members of the Labour Party have also said it played a significant role in the defeat - while pointing to the fact Uxbridge has always been Tory and did not even turn red in the 1997 landslide election victory.

However, left-wing group Momentum have said the failure to gain the seat goes beyond ULEZ.

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There have been reports the Corbyn-supporting Uxbridge CLP supported a different candidate than Mr Beales.

A Momentum source said: "This result should be a wake-up call for Keir Starmer: stop the purges, respect members and offer our core vote some real hope."

The Uxbridge by-election was one of three triggered by scandal and a row over Mr Johnson's honours list - with the Tories suffering two bruising losses to Labour and the Lib Dems in what were considered safe seats.

At the other end of the country, in Selby and Ainsty, Labour overturned a Conservative majority of 20,137 - the largest majority reversed at a by-election.

Labour leader Sir Keir Starmer said voters in the North Yorkshire constituency have let out a "cry for change" as he celebrated the win.

On Uxbridge, Sir Keir said: "Uxbridge was always going to be tough. We didn't take Uxbridge in 1997 and we knew ULEZ was going to be an issue.

"And of course we all need to reflect on that, including the mayor needs to reflect on that."

However, Mr Khan has stood by his decision - even as he admitted being "disappointed" in the result.