John Yates, the Assistant Commissioner of the Metropolitan Police, has resigned from his position following criticism of a previous inquiry into phone hacking and claims that he was too close to executives at News International.
The Met said in a statement: "Assistant Commissioner John Yates has this afternoon indicated his intention to resign to the Chair of the Metropolitan Police Authority. This has been accepted. AC Yates will make a statement later this afternoon."
Mayor of London Boris Johnson said at City Hall that Yates decided to resign after being told he would be suspended because his conduct was being referred to the Independent Police Complaints Commission.
On the resignation of Yates and also that of Sir Paul Stephenson, who stepped down as Met commissioner on Sunday, Johnson said that "in both cases the right call has been made".
"We have to recognise that the nexus of questions about the relationship between the Met and the News of the World was likely to be distracting to both officers in the run up to the Olympic games," Johnson said. "Now is the time to get to the bottom of all of these questions."
Johnson defended his actions over phone hacking and said that he had "changed his mind" since saying that the scandal was "codswallop" in September 2010. He admitted his language was "colourful" but said it was a result of "heavy provocation from a member of the London Assembly". He also said that he had not met Neil Wallis, the former News of The World executive who became a PR adviser to the Met.
Asked to back the prime minister over his decision to hire Andy Coulson, Johnson simply said that he did not consider the Met's situation to be equivalent to that of Number 10.
Home Secretary Theresa May expressed her "gratitude" to Yates for his work at the Met.
"I want to put on record my gratitude to John Yates for the work he has done while I have been home secretary, to develop and improve counter-terrorism policing in London and indeed across the UK," she said.
The announcement of Yates' resignation comes after politicians and an independent member of the MPA called for Yates to stand down, and after the Home Affairs select committee recalled him to appear before them on Tuesday.
Yates appeared last week before the same committee, where he defended his role in relation to a previous inquiry into phone hacking at News International, which failed to uncover evidence of the practice.
Earlier on Monday, Boris Johnson, speaking to BBC Radio 4, said that he was "very, very angry" that City Hall was not told about the Metropolitan Police's employment of Neil Wallis, the former-News of The World executive arrested last week.
Stephenson resigned on Sunday, just hours after Rebekah Brooks, former News International chief executive, was arrested in connection to investigations into allegations of phone hacking and corruption at the company.
However her lawyer Stephen Parkinson said on Monday that Brooks still intended to appear before a Commons culture select committee on Tuesday, alongside Rupert Murdoch, the News Corp chairman, and his son James.
He added that his client was "not guilty of any criminal offence".
"The position of the Metropolitan Police is less easy to understand. Despite arresting her yesterday and conducting an interview process lasting nine hours, they put no allegations to her, and showed her no documents connecting her with any crime," he told reporters on Monday.
"They will in due course have to give an account of their actions, and in particular their decision to arrest her, with the enormous reputational damage that this has involved."
In response to the resignations, home secretary Theresa May announced a number of personnel changes and a review of police corruption. Tim Godwin will act as temporary deputy commissioner, Cressida Dick will take over counter-terrorism from Jon Yates and Elizabeth Filkin, former Parliamentary Commissioner for Standards, will look at police and press relations. She also said more funds would be made available to the IPCC.