In full: resignation statement | How we predicted his departure | What he said in response | Picture slideshow

Sir Ian Blair was forced to resign as Commissioner of the Metropolitan Police yesterday in a swift political coup at the top of Scotland Yard.

Boris Johnson, the Conservative Mayor of London, asked Sir Ian to go, hours after taking control of London’s police authority. It is understood that he threatened Mr Blair with non-co-operation if he did not quit.

The commissioner went to what he thought was a routine meeting with Mr Johnson and two officials on Wednesday only to be told that the mayor wanted him to stand down. “The only topic of discussion was the strategic direction of the force and it was underlined to him that a change of leadership was necessary,” a source told The Times.

Sir Ian was caught by surprise but accepted that he could not carry on without the support of the mayor and police authority. The meeting was said to have been conducted in a “professional and mature” manner. Government officials are furious, however, that the Home Secretary was not informed until she was contacted by the commissioner yesterday. Jacqui Smith and Mr Johnson are obliged by law to work together to appoint a new commissioner but the process is likely to be beset by political wrangling.

Labour made it clear that Ms Smith would not be dictated to by a Tory mayor. Mr Johnson’s aides said that it would be “obscenely inappropriate” if she were to overrule the mayor.

Although Sir Ian has been an unpopular leader, there is anger in the police service that its most senior officer has fallen victim to party politics. Some candidates to succeed him might be reluctant to seek the job without assurances that they will not be subjected to similar political interference.

The commissioner’s position had become increasingly tenuous, with allegations that he acted improperly in the award of Yard contracts to a friend and claims of racial discrimination by senior Asian officers — both of which Sir Ian denies. The Met is also facing a testing examination of its actions at the inquest for Jean Charles de Menezes, shot dead by armed officers who mistook him for a suicide bomber.

Sir Ian’s resignation statement placed responsibility for his departure at Mr Johnson’s door. “At a meeting yesterday the new mayor made clear, in a very pleasant but determined way, that he wished there to be a change of leadership at the Met,” he said. “I understand that to serve effectively the commissioner must have the confidence of both the mayor and the Home Secretary. Without the mayor’s backing, I do not consider that I can continue in the job.

“Personally I see no bar to working effectively with the new mayor but it is there that we differ and hence I am unable to continue.”

Mr Johnson said that Sir Ian had a distinguished record but the Met needed change. “There comes a time in any organisation when it becomes clear it would benefit from new leadership and clarity of purpose. I believe that time is now,” he said.

Sir Ian stands down on December 1. Sir Paul Stephenson, his deputy, is regarded as the favourite to succeed him. Other leading candidates are Sir Hugh Orde, Chief Constable in Northern Ireland, and Bernard Hogan-Howe, police chief of Merseyside.

Sir Ian, 55, is entitled to a full police pension. On the commissioner’s £240,000 salary that is estimated to be worth about £160,000 per year.

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