Drug and drink addict prisoners will receive special rewards if they go “cold turkey” and kick their habit in jail.
The prisoners will receive gym sessions, extra visits, and televisions if they quit.
Justice Secretary Dominic Rabb is to create 100 units inside jails where offenders agree to regular drug tests.
If they stay clean, they will be given in-cell televisions, extra family visits and access to cooking facilities.
The units are part of a £120 million scheme to help rehabilitate prisoners.
Mr Raab said:
“Drugs trap criminals in a destructive cycle of offending and prevents them from getting their lives back on track.
“Our plan will get offenders into rehab earlier, get them off all drugs permanently and support prisoners once they’re released into the community.
“That will drive down reoffending and make our streets safer.”
It’s estimated illegal drug use costs the taxpayer £22 billion each year – including NHS treatment, dealing with addicted prisoners and tackling drug-related crime.