Sir Keir Starmer has said Labour's Mayor of London should reflect on the expansion of the city's Ultra Low Emission Zone, after the party narrowly missed out on victory in the Uxbridge and Ruislip by-election.

The Conservatives won 13,965 votes in Boris Johnson's old seat, just 495 more than Labour's 13,470.

The by-election effectively became a referendum on Sadiq Khan's plan to expand the anti-pollution measures to London's suburbs from the end of the August. 

Labour had more luck in Selby and Ainsty where they overturned a Tory majority of more than 20,000.

The swing from Conservatives to Labour of 23.7 percentage points is the second largest swing managed by Labour at a by-election since 1945.

Sir Keir went to the North Yorkshire constituency – not far from Mr Sunak’s seat – to celebrate the “historic” victory at Selby Town Football Club.

READ MORE: Sunak insists next general election not 'done deal'

He told supporters it was the “biggest majority we’ve ever turned over in the history of the Labour Party”.

“You voted for change. You put your trust in the Labour Party, and we hear you,” he said.

“We hear that cry for change away from the chaos, away from those rising bills, the crumbling public services – a cry for change and we will deliver.”

Asked about Mr Johnson's seat, 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.”

Labour candidate Danny Beales had distanced himself from the policy, saying it was “not the right time” to expand the £12.50 daily charge for cars which fail to meet emissions standards.

The defeat in the seat was dubbed “Uloss” by a party insider.

A source close to the mayor told the Evening Standard: “Winning Uxbridge and South Ruislip was always going to be a struggle for Labour.

“Labour hasn’t won this seat for five decades and Tony Blair didn’t even win it during the 1997 landslide.

“Sadiq has always been clear that expanding the ULEZ was a really difficult decision, but necessary to save the lives of young and vulnerable Londoners.”

 

READ MORE: Byelection results: Thumping defeats for Sunak’s Tories in two seats

 

Polling expert Professor Sir John Curtice said the by-elections suggest the Tories are in “deep electoral trouble”, with the results showing the Conservatives are 21 percentage points behind, similar to the national polling.

He noted the similarity to the run up to the 1997 Labour landslide, telling BBC Radio 4’s Today programme “history is not bound to repeat itself” but the precedent indicates the difficulty the Tories are in unless they can turn things around.

But he said Labour must ask why its hold on the electorate is “apparently so weak” that when a local issue like Ulez comes up they “don’t perform as they should”.