Boris Johnson has vowed to come down hard on crime by extending police stop-and-search powers and toughening up prison sentences.
The prime minister, echoing the words of home secretary Priti Patel last week, said he wanted criminals to be afraid, rather than the public.
He also announced plans to invest £2.5bn to create 10,000 new places to relieve the pressure on overcrowded jails.
It follows the government’s announcement that an extra 20,000 police officers would be recruited over the next three years.
Mr Johnson revealed the plans for a crackdown on violent criminals in an article for the Mail on Sunday, in which he cited rising knife crime and the recent machete attack on a police officer.
We have the impression of a growing culture of insolence on the part of the thugs; and in the face of that sense of impunity entirely misplaced I believe the British public knows instinctively what we must do, he said.
We need to come down hard on crime. That means coming down hard on criminals. We need to reverse the balance of fear. I want the criminals to be afraid not the public.
Under the government’s plans, an existing pilot project, which allows police to deploy stop-and-search powers in an area without the authorisation of a senior officer, will be extended to cover an additional 8,000 officers in England and Wales.
Mr Johnson acknowledged the move would be controversial but said he believed it would have the backing of the parents of those children most at risk of getting caught up in knife crime.
We are making clear that the police can and should make use of their stop-and-search powers, he wrote.
I know that left-wing criminologists will object. And, of course, it is right that stop-and-search should be done courteously and in accordance with the law.
But I also know that the people who back this intervention most fervently are often the parents of the kids who are so tragically foolish as to go out on the streets equipped with a knife, endangering not only the lives of others but their own.
The Prime Minister said the £2.5bn investment in the prison system approved by Sajid Javid, the chancellor was long overdue.
Mr Johnson said that he wanted to reduce overcrowding, beef up security, and do more to educate in jail.
He wrote: It is not enough just to catch the criminals, punish them and deter them from further crime. We must also do far more to turn their lives around, because our penal system is woefully ill-equipped to rehabilitate and reform.
The prime minister is also expected to pledge to end the automatic release of serious criminals who are currently freed after serving half of their sentence.
Mr Johnson wrote: In the past five years, we have seen literally hundreds of convicted rapists who have come out of prison commit another sexual offence.