Blair still does not understand why he was forced to resign
Sir Ian Blair says he was forced out of the job of Metropolitan Police commissioner by Boris Johnson "to show the power of the London mayoralty".
He told BBC One that the move in 2008 had "dangerous implications" for the future of British policing.
Safeguards that existed in the US where politicians could hire and fire police chiefs were not in place here, he said.
A spokesman for the mayor said Sir Ian had given "committed service", but the Met had "moved on" from the issue.
Sir Ian resigned in October last year after facing a number of controversies.
During his tenure, he presided over a series of reforms, including the introduction of community support officers, but his close relationship with former prime minister Tony Blair was disliked by some senior officers.
He was also criticised over his handling of the shooting of Jean Charles de Menezes in 2005 and for publicly questioning why the murders of Holly Wells and Jessica Chapman, in Soham, had been such a big news story.
Mr Johnson said at the time of Sir Ian's departure that he wanted "new leadership" at the Met, but the former commissioner said he still did not understand why he had been forced to resign.
"What happened has some dangerous implications for the future of policing," he told the BBC's Andrew Marr show.
"There is a system in which chief officers are appointed [and] they are operationally independent. If, at a stroke, they can be removed then the system has been changed. If you like, an external species has been brought into the indigenous situation."
We now have new leadership in place and the Met has moved on
Boris Johnson's spokesman
Sir Ian, who is promoting his autobiography, said Mr Johnson had effectively introduced the US situation where "chief officers come and go at the behest of the mayor".
"There's nothing wrong with the American system, but it's got a lot of checks and balances that the British don't have," he added.
Asked whether such a system would make the public less safe, he said "absolutely".
"There are 17,000 separate law enforcement agencies in the United States, some of which are of a very poor standard."
Sir Ian also said Conservative plans to introduce directly elected local police chiefs to replace existing police authorities would "end operational independence".
His objection was not, he insisted, "a party political point", adding: "If the Labour party was putting forward this proposal I would say it is as ill-thought out and historically ignorant as it is at the moment."
Sir Ian said he admitted in his book "that I made some mistakes", but "didn't make some mistakes about some other things".
He rejected the idea that he was personally "culpable" for Mr de Menezes' death, but said he did feel "personally accountable".
He also added that he was the first commissioner "to live in the global, 24-hour media age" and as a result, had become "a figure of political and press debate".
In a statement, Mr Johnson's spokesman said he had "committed to providing strong leadership in reducing crime and violence in London" during his mayoral election campaign.
"Ian Blair gave committed service to the Met as commissioner, for which the mayor and Londoners will always be grateful," he said.
"We now have new leadership in place and the Met has moved on."
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