Formally, the Metropolitan Police commissioner is appointed by the Queen on the recommendation of the prime minister.
In practice – and especially with the prime minister now being investigated by the force – it is the choice of the home secretary. Indeed, until 2000 and the establishment of the Greater London Authority, the appointment was the responsibility of the home secretary. It reflected the force’s special status and national policing role, such as in counterterrorism.
Now, although the formalities are still observed, the Met commissioner is not so much at the pleasure of Her Majesty but at the pleasure of the directly elected mayor of London. Without the public confidence of the mayor, any incumbent or applicant for the role cannot serve for long. That is one of the most significant lessons of the resignation of Dame Cressida Dick.