UK by-elections 2023: Tories hold Uxbridge and South Ruislip while Labour shocks Selby and Ainsty

The three by-elections were split amongst the main parties on a night of high drama that could be a precursor to the next general election.

The Labour party will have felt mixed emotions, as despite overturning the biggest Tory majority in its history in Selby and Ainsty, the Conservatives held Boris Johnson's old seat in Uxbridge and South Ruislip. The west London constituency was the first to declare, and after a recount Tory Councillor Steve Tuckwell has named the new MP beating Labour Danny Beales by just 495 votes.

There was 6.7 percentage point swing in the share of the vote from Conservative to Labour, with a 7.6 point swing needed for Keir Starmer's party to take the seat. Tuckwell put his success down to the unpopularity of the expansion of the Ultra Low Emission Zone, a charge on polluting cars.

He said: "[Mayor] Sadiq Khan has lost Labour this election. It was his damaging and costly ULEZ policy that lost them this election. This wasn’t the campaign Labour expected and Keir Starmer and his mayor Sadiq Khan need to sit up and listen to the Uxbridge and South Ruislip residents.”

Given the Conservatives were expected to lose all three elections, holding on to a seat will be seen as a major win for Rishi Sunak. And there will be concerns at Labour HQ that a single issue, like the ULEZ, could derail their campaign so badly.

However Labour had better news from North Yorkshire, with the party overturning the biggest Tory majority in its history to win Selby and Ainsty. Former Conservative MP Nigel Adams, who resigned after his ally Boris Johnson did, previously had a majority of 20,137 in a rural seat. However, Labour's 25-year-old candidate Keir Mather, who will become the youngest MP in Parliament, overturned that with 16,456 votes, a fairly sizeable majority over Tory Claire Holmes, who received 12,295 votes.

Starmer described this victory as a "historic result". He said this shows "that people are looking at Labour and seeing a changed party that is focused entirely on the priorities of working people with an ambitious, practical plan to deliver".

“Keir Mather will be a fantastic MP who will deliver the fresh start Selby and Ainsty deserves," Starmer said. “It is clear just how powerful the demand for change is. Voters put their trust in us — many for the first time." There was a 23.7 percentage point swing in the share of the vote from the Conservatives to Labour.

Despite the loss in west London, winning a traditionally safe Tory seat in North Yorkshire is a huge boost for Labour - who would not even have had Selby and Ainsty on their target list to win the next election.

The Liberal Democrats claimed another scalp of the Conservatives in the South West, as candidate Sarah Dyke overturned a majority of more than 19,000 to win in Somerton and Frome. Former Tory MP David Warburton resigned after admitting cocaine use amid allegations of sexual harassment.

The 29.0 point swing at Somerton is larger than the one achieved by the Lib Dems when they defeated the Tories at the by-election in Chesham & Amersham in June 2021 (25.2 points) and just below the swing when they beat the Tories at Tiverton & Honiton in June 2022 (29.9 points).

Liberal Democrat Leader Sir Ed Davey said said the “stunning victory” showed his party was “firmly back” in its former West Country stronghold. “Sarah Dyke will be an incredible local champion for the people of Somerset who have been neglected for far too long,” he said.

“She will fight for stronger local health services, better access to GPs and a fair deal for rural communities during this cost of living crisis. The people of Somerton and Frome have spoken for the rest of the country who are fed up with Rishi Sunak’s out-of-touch Conservative government.”