From yesterday, forces in badly-affected areas such as South Yorkshire and West Yorkshire can activate powers designed to head off violence at a lower level of seniority.
Home Secretary Sajid Javid has also made it simpler for police to use Section 60 of the Criminal Justice and Public Order Act 1994.
This allows officers to stop and search anyone in a designated area for a limited time if serious violence is anticipated.
Once authorised, police can stop and search people or vehicles regardless of whether they have reasonable grounds for suspecting they will find offensive weapons or dangerous items.
Mr Javid has now lifted two conditions introduced in stop and search guidance rolled out in 2014 when Theresa May was home secretary.
The Best Use of Stop and Search Scheme, which all forces are signed up to, requires a section 60 order to be signed off above chief superintendent rank, and states the authorising officer must reasonably believe serious violence “will” take place.
Under the changes announced this weekend, which initially apply to seven forces, the rank at which a section 60 can be approved has been lowered to inspector.
This will result in at least 3,000 more officers being able to authorise the use of the powers, officials estimate. Mrs May, who will host a summit on serious youth violence today, said stop and search is an “important tool” in the fight against knife crime.
The Section 60 changes will initially apply in London, West Midlands, Merseyside, South Yorkshire, West Yorkshire, South Wales and Greater Manchester for up to a year.
West Yorkshire Police Assistant Chief Constable Catherine Hankinson said: “The need to utilise Section 60 of the Criminal Justice and Public Order Act does not occur often within West Yorkshire.
“However we welcome these proposals as we recognise there may occasionally be a legitimate need to invoke these powers to adequately respond to critical situations and keep communities safe. Use of Section 60 will continue to be very carefully considered prior to its authorisation and we are committed to constantly engaging with the communities we serve.”
South Yorkshire’s Chief Constable also welcomed the move.