MPs are set to address Britain's 43-year-old drug laws today in the first Commons debate of its kind in a generation.
The debate follows the findings of a report which shows that a punitive approach to drug abuse, including locking up addicts, fails to curb levels of addiction.
Ministers have visited 10 other countries which have relaxed their laws on drugs - including Portugal where since decriminalising levels of punishment for personal drug use in 2001 has seen a fall in addiction and drug-related deaths.
The review of other countries’ experience of drugs legislation was set up 18 months ago by the Home Secretary Theresa May and conducted by Liberal Democrat ministers, Jeremy Browne and Norman Baker.
It was completed in July but publication was delayed, provoking accusations from Mr Baker that senior Conservatives were attempting to bury its findings.
The report will suggest treating possession of drugs as a health issue rather than a criminal one.
Britain's drug laws: A brief overview
When were the drug laws brought in?
The Misuse of Drugs Act 1971 divided “controlled drugs” into three levels of seriousness. Some details have been revised since then, but this legislation remains the basis for the UK’s drug laws.
Which drugs are in class A, and what are the penalties?
Heroin, cocaine and crack, ecstasy, LSD, methadone, methamphetamine (crystal meth) and magic mushrooms are considered the most dangerous drugs. Possession can mean seven years in prison, an unlimited fine, or both. Dealing carries a maximum life sentence.
What about class B?
These include amphetamine, barbiturates, codeine, ketamine and cannabis. Possession carries a maximum penalty of seven years’ jail and/or an unlimited fine; supply and production carries up to 14 years in prison. In practice most people prosecuted for class B drugs receive small fines or a caution.
Has cannabis always been class B?
It was downgraded to class C between 2004 and 2009 under the Blair government following warnings the classification lacked credibility. It was moved back to class B by the Brown government.
Is there a case for a review?
Yes. The range and type of drugs available has changed dramatically in 43 years, and critics say the categories do not reflect the danger or addictiveness of different drugs.