Drug users will no longer be prosecuted for possessing heroin, cocaine or cannabis under a police force’s pilot scheme.
West Midlands Police will automatically register adult and teenage drug users on its Divert programme rather than applying the law.
Drug addicts will not face charges even after repeated offences, as long as they remain engaged with the scheme.
The Divert programme is expected to run for one year and does not enrol those who commit drug supply offences. Another seven police forces are using or developing similar programmes.
It comes as Police and Crime Commissioners in the West Midlands and North Wales say they want to provide rooms for drug addicts to inject themselves with medical-grade heroin.
David Jamieson and Arfon Jones have claimed that such schemes would help reduce drug-related crime.
However, the Home Office has said: “The decriminalisation of drug possession in the UK would not eliminate the crime committed by the illicit trade, nor would it address the harms associated with drug dependence and the misery that this can cause to families and communities.”
Last year, a senior police officer also warned that legalising drugs would not fix the problems of drug abuse or criminal gangs.
Chief Constable Andy Cooke, who leads Merseyside Police, said: “It isn’t going to solve the problem of people taking other drugs and it is not going to stop the violence.”