[JURIST] Sir Ian Blair [official profile] resigned Thursday from his position as Commissioner of London's Metropolitan Police Service ("Met") [official website], effective December 1, 2008. Blair cited a strained relationship with the newly-elected mayor of London, Boris Johnson [official profile], and the mayor's decision for new leadership at the Met as the leading factors in his decision to resign. In a letter [text, PDF] UK Home Secretary Jacqui Smith [official profile] thanked Blair for his leadership through the July 7, 2005 London transit bombings [JURIST news archive]. In a corresponding letter [text, PDF] to Johnson, Smith indicated that the search for Blair's replacement would begin immediately. In a prepared statement [text], Blair said:

I am resigning in the best interests of the people of London and the Metropolitan Police Service. I would have wished to continue to serve Londoners until my term of office expired in February 2010. However, 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. 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. The home secretary has asked that I should stay for enough time for the process of appointing my successor to be got under way. I will therefore leave office on December 1, 2008, giving the home secretary and Metropolitan Police Authority time to make plans for the appointment of my successor. I offer Boris Johnson and his team at City Hall and at the Police Authority the very best of fortune.

BBC News has more. The New York Times has additional coverage.

Blair's three-year tenure as Commissioner of the Met was dominated by terrorism-related issues. He was ultimately cleared of any wrongdoing [JURIST report] in the shooting of Jean Charles de Menezes [BBC profile] in a London Tube station after he was mistakenly identified as a terrorist after a second and this time failed series of bombings in late July 2005, but his public reputation was sullied by the incident. Blair also advocated extending the current 28-day detention limit for uncharged terrorism suspects [JURIST news archive], which soon may increase to 42 days if legislation now before Parliament is passed.