Labour sources also said Sir Keir Starmer, the party leader, had also not been informed of Dame Cressida’s departure in advance.

Sir Paul Stephenson, a former Scotland Yard commissioner, accused Mr Khan of “political opportunism” and “grandstanding”.

“For Sadiq Khan to go public in the way he did smacked of a politician putting up a smokescreen rather than having an appropriate and sensible conversation in private to lead to a dignified outcome,” he said. “It appeared to be political opportunism and grandstanding by Sadiq Khan. I think that is very sad.”

Mr Khan said on Wednesday that he wanted Dame Cressida to come up with a plan within “days and weeks” to rid the force of sexism, racism and homophobia following a series of scandals.

Just hours before her departure, she had insisted: “I have absolutely no intention of going.”

However, following an exchange with Mr Khan on Thursday afternoon, the 61-year-old said it was clear he no longer had confidence in her ability to deliver the change needed in the force.

‘The greatest honour and privilege of my life’

In a statement on Thursday, Dame Cressida said: “It is with huge sadness that, following contact with the Mayor of London today, it is clear that the Mayor no longer has sufficient confidence in my leadership to continue. He has left me no choice but to step aside as Commissioner of the Metropolitan Police Service.

“Undertaking this role as a servant of the people of London and the UK has been the greatest honour and privilege of my life.”

Dame Cressida said she had agreed to stay on in the role temporarily until her successor was appointed.

The resignation also comes at a sensitive time with the Metropolitan Police mid-way through the “partygate” investigation, which could see the prime minister fined for breaking lockdown rules.

Mr Khan, who up until recently was understood to have a good relationship with the commissioner, had said he was not satisfied that Dame Cressida – the first female and openly gay head of Scotland Yard – was doing enough to root out racism, sexism, homophobia, bullying, discrimination and misogyny in the ranks.

The force has been dogged by several controversies, which critics say pointed to a rotten culture.

Last week, a police watchdog report revealed officers at Charing Cross police station had shared vile social media messages in which they had joked about rape and killing black children.

The Met also failed to root out Wayne Couzens, the police officer known as “the rapist” who went on to murder Sarah Everard. Officers were also investigated for sharing images of two murdered sisters on WhatsApp.

The Metropolitan Police’s handling of a subsequent vigil on Clapham Common hugely damaged its standing among women and Londoners, even though the force was ultimately cleared of wrongdoing.