London mayoral candidate Rory Stewart has dropped out of the race after the coronavirus crisis forced a year’s delay.
The former Tory cabinet minister said it was impossible to ask unpaid campaign volunteers to work for another 12 months.
The independent candidate said it had been an “agonising decision” for him to make.
The announcement comes on the eve of what would have been polling day.
In a statement Mr Stewart said: “I firmly believe London is the greatest city on earth – and it’s courageous response to Covid-19 proves that more than ever.
“It would have been the honour of my life to serve the city as mayor, but while the considerable challenges of running as an independent were manageable for a normal race they are forbidding for an extended and delayed election.”
The former MP for Penrith and The Border left parliament in October 2019 to run as an independent candidate.
He had campaigned for the Conservative leadership last summer.
But after Boris Johnson became prime minister, Mr Stewart was one of 21 Conservative MPs expelled from the party for rebelling over Brexit.