Stop-and-search powers will be used “properly” to address knife crime in London, Metropolitan Police Commissioner Cressida Dick has said.

Britain’s leading police officer spoke after a spate of new year stabbing deaths prompted London mayor Sadiq Khan to promise a “significant increase” in the use of the power.

Stop and search has attracted criticism in the past that it disproportionately targets people from ethnic minorities, and Mr Khan’s comments were questioned by his Labour colleague David Lammy.

But Ms Dick, speaking as she attended a police and community search for weapons on a north London housing estate, said her officers were professional and well-trained, and searches would be captured on body camera.

She said: “I think the public can be very assured that where there is proper grounds to use the power, the power will be used properly.

“Where we have intelligence, where we know there is a real problem with knife crime, where we know someone is a habitual knife-carrier, I think the vast majority of the public would expect us to be using the law and our powers to its full effect.

“The last thing I want is for this to damage community relationships but I actually feel that we have the ability now, between the people of London and the Met, to bear down on violent crime through a variety of methods, not least through stop and search, and to do that in a way that actually improves community relationships rather than damaging them.”

Four young men were stabbed in London in the space of 48 hours at new year, two in north London, one in the East End and a fourth in south-west London.

The death of an 18-year-old in Enfield on New Year’s Eve took the number of people stabbed to death in the capital last year to 80, Scotland Yard said.

Eighteen involved victims under the age of 19.

Last week Mr Khan wrote in the Evening Standard that 2018 would see a “a tougher crackdown” on violent crime.

He wrote: “This will include a significant increase in the use of targeted stop and search by the police across our city.

“I know from personal experience that when done badly, stop and search can cause community tensions. But when based on real intelligence, geographically focused and performed professionally, it is a vital tool for the police to keep our communities safe.”

Metropolitan Police Commissioner Cressida Dick joins police officers conducting a weapons sweep in Islington, north London (Dominic Lipinski/PA WIRE)
Ms Dick joins police officers conducting a weapons sweep in Islington, north London (Dominic Lipinski/PA)

Tottenham MP Mr Lammy, who led a review of how the legal system treats ethnic minorities, told The Guardian he was “disappointed that the vexed issue of stop and search is again being used as a political football, and I have made my views clear to the mayor of London”.

The weapons sweep in Islington saw Ms Dick joined by deputy mayor for policing Sophie Linden and George Kinsella, whose son Ben was stabbed to death in June 2008.

Ms Dick said the rise in knife crime in London was “stabilising” and 5,000 people had been arrested in the past eight months.

She spoke of visiting the families of violent crime victims, saying: “The words they often use are ‘absolutely senseless’.

“When you look at the circumstances in which people are actually dying, it’s usually quite a minor dispute, it’s an argument about a girl, it’s a falling-out about money, it’s about drugs and sometimes it’s actually mistaken identity.

“Whatever it is, it is senseless and it is appalling and for these people, they have lost their loved one, their lives are ruined forever.”