Washington [US], May 5: Sir Keir Starmer has added to Tory election misery with a string of Labour victories in regional mayor contests.
After a bruising set of local council results, the Tories had been pinning their hopes on incumbent Andy Street retaining the West Midlands.
But he lost out by a margin of just 1,508 votes to Labour's Richard Parker, dealing a further blow to Rishi Sunak.
The prime minister now faces the task of rallying his battered party ahead of a general election due within months.
The dramatic West Midlands defeat - only confirmed after a nail-biting recount - rounded off a dismal set of results for the Conservatives with Ben Houchen in Tees Valley the party's only mayoral success out of 11 contests across England.
In local authority elections, the Tories lost more than 470 councillors and control of 10 councils.
The party also failed to hold on to the parliamentary seat in Blackpool South, where it lost to Labour and were almost beaten into third place by Reform UK, a successor to Nigel Farage's Brexit Party.
Despite the poor performance, talk of a possible move by discontented Conservative MPs to oust Mr Sunak as party leader appears to have dissipated.
Writing in the Sunday Telegraph, former home secretary and Sunak critic Suella Braverman said: "We must not change our leader. Changing leaders now won't work: the time to do so came and went.
"The hole to dig us out of is the PM's, and it's time for him to start shovelling."
Mr Sunak said it had been disappointing to lose Mr Street, and "dedicated" councillors, but said by sticking to the party's plan "we will secure our borders, grow the economy and create opportunities so everyone in this great country can thrive and prosper."
Celebrating with supporters in Birmingham, Labour leader Sir Keir said: "We started in Blackpool with a 26% swing and we've ended in the West Midlands with our new mayor Richard Parker, and plenty in between - mayoralties, councils and our police and crime commissioners."
He called the "phenomenal" result in the West Midlands "beyond our expectations", adding voters had "had enough of 14 years of decline, chaos and division" and urged Mr Sunak to call a general election.
Elsewhere, smaller opposition parties performed well with the Liberal Democrats returning 521 councillors - more than the Conservatives on 513 - while the Greens secured their highest-ever tally of seats.
Of the 11 mayoral races, Labour won in 10 areas - the East Midlands, Greater Manchester, Greater London, Liverpool City Region, the North East, Salford, South Yorkshire, the West Midlands, West Yorkshire, and York and North Yorkshire.
While the party has plenty to smile about this weekend, it will have concerns about an apparent backlash in some Muslim areas over its stance on Gaza.
In 58 local council wards analysed by the BBC, where more than one in five residents identify as Muslim, Labour's share of the vote was 21% down on 2021, the last time most seats were contested.
The potential impact on a general election is unclear, however, with some evidence the biggest drops in support are largely confined to areas where the party's support was already very strong.
Asked if he was worried about losing votes over the issue, Sir Keir said: "Where we have not been able to persuade people who might otherwise have voted Labour it is important for me to acknowledge that, to say I have heard, I've listened and I am determined to meet the concerns they have."
It was a downside to an otherwise positive performance for Labour, which saw it gain 185 councillors to take control of eight councils.
Meanwhile, the Liberal Democrats are celebrating gaining more than 100 councillors and taking control of the councils in Dorset and Tunbridge Wells.
However, it missed out on securing a majority of seats in its target areas of West Oxfordshire and Wokingham.
Party leader Sir Ed Davey said: "Up and down the country Conservative MPs will be looking over their should terrified of the Liberal Democrats who have won more seats than them in this election."
The Green Party hailed a "record-breaking campaign" after winning a total of 181 council seats, an increase of more than 70.
Reform UK performed strongly in the Blackpool South by-election coming just 117 votes behind the Conservatives.
George Galloway's Workers Party of Britain won four council seats including one in Manchester where they unseated Labour's deputy leader of the council Luthfur Rahman.
The Women's Equality Party won its first council seat when Stacy Hart was elected to Basingstoke and Deane Borough Council.
Source: Fijian Broadcasting Cooperation