A recount has been ordered in the by-election in Boris Johnson’s former seat in a sign that Labour may fail to oust the Tories.

The former prime minister held Uxbridge and South Ruislip with a majority of 7,210 in 2019 but Sir Keir Starmer’s party had been hopeful of winning the by-election.

But Labour sources have become increasingly pessimistic about their chances, with the expansion of the Ulez low emission zone charge to the west London seat a major factor.

Labour’s London mayor Sadiq Khan plans to extend the zone to cover the whole of the capital on August 29, meaning drivers will face a £12.50 daily charge unless their car meets stringent emissions rules.

Labour’s candidate Danny Beales was thought to be around 400 votes short of the Tories when the recount was ordered.

If Tory Steve Tuckwell manages to retain the seat it will mean Rishi Sunak has been spared the prospect of being the first prime minister since 1968 to lose three by-elections on the same day.

But the Prime Minister still faces the prospect of the Liberal Democrats overturning a 19,213 Tory majority in Somerton and Frome – Sir Ed Davey’s party believe they have “romped home”.

And in Selby and Ainsty Labour hope to take a seat where the Conservatives were defending a 20,137 majority.