The return of stop and search has helped to drive down the murder rate in the capital by a quarter over the past year, Britain’s top police officer has said.

Cressida Dick, commissioner of the Metropolitan Police, said that massive increases in its use had also contributed to a 15 per cent reduction in the number of under-25s being stabbed in London.

The tactic was discouraged by Theresa May when she was home secretary on the basis that it was resulting in a loss of public confidence in the police and unfair targeting of young black men.

In stark contrast Sajid Javid, the present home secretary, has championed it as part of robust responses to the violent crime epidemic.

The reduction in the murder