In a Statement from Commissioner Sir Ian Blair said "It is the duty of the Commissioner to lead the Met through good times and bad: to accept the burdens and pressures of office and, above all, to be a steward of the Service he commands. However, I have today offered my resignation as Commissioner to the Home Secretary, which she has reluctantly but graciously accepted.

I am resigning not because of any failures by my Service and not because the pressures of the office and the many stories that surround it are too much. 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 underway. I will therefore leave office on 1 December 2008, giving the Home Secretary and the MPA 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. I say to the people of London that I believe that, in the Metropolitan Police Service, they have a quite wonderful institution made up of extraordinary men and women, who daily risk their lives on your behalf. I say to those men and women and those staff who support them that they are part of one of the greatest police services in the world. This great institution, which I have served for 28 out of my 34 years as a police officer, will always have a central place of affection in my heart. "

Responding to the resignation of Sir Ian Blair as Commissioner of the Metropolitan Police, Shadow Home Secretary, Dominic Grieve, said: “This is the right decision. We have been calling for Sir Ian to step down for almost a year - since the serial and systematic failings at the Metropolitan Police disclosed during the De Menezes trial - whilst Cabinet Ministers from the PM onwards continued to express total confidence in him.

“It is now clear that they have shown a serious lack of judgment about the leadership of the most important police force in Britain. It is vital that a successor is appointed who can restore public confidence.”