Councils have warned the Government against making further funding cuts to youth offending teams as knife crime continues to come under the spotlight.
Efforts to stop children joining gangs and becoming involved in violent crime will be "undermined" if funding to tackle youth offending is cut further, the Local Government Association (LGA) said.
Figures show that youth justice grants, which fund the work of youth offending teams within councils, have been halved from £145 million in 2010/11 to £71.5 million in 2018/19, the LGA added.
The warning comes amid a string of high-profile stabbings across the country which have led to the issue being described as a "national emergency".
The LGA said councils were waiting to find out how much funding they would receive for 2019/20, but said "at the very least" it should match last year's amount following the recent surge in knife crime.
Coun Anntoinette Bramble, chairwoman of the LGA's children and young people board, said: "The recent spate of tragic violence across the country underlines the importance of investing in services which protect and support young people, keeping them safe from the lure of gangs or from becoming involved in serious crime.
"Youth offending teams within local authorities have an outstanding record of reducing youth crime and making a real difference to young people's lives, but they are under huge pressure after seeing their government funding halved.
"We share the Government's determination to tackle youth crime, but it needs to properly fund the services that work most closely with young people at risk of offending.
"It is also important that there is no delay in councils finding out how much funding they will be allocated, so they can effectively plan services to support young people."
Youth offending teams have been credited with helping prompt an 86% decrease in first-time entrants to the youth justice system over the past 10 years, as well as a 78% drop in arrests.
Over the same period, the number of youth cautions handed out dropped by more than 100,000, or 91 per cent.
Meanwhile, police forces across the UK have asked the Government for emergency funding to help them bear down on violence now.
The National Police Chiefs' Council (NPCC) confirmed on Friday it had sent information to the Home Secretary concerning how much money was needed.
Sajid Javid had previously pledged to do "everything I can" to provide police with the resources required.
Chancellor Philip Hammond came under fire for saying that police should shift existing resources into tackling knife crime rather than expect more funding.