The ins and outs of UK cannabis law - and calls to decriminalise it

Sir Sadiq Khan says the current rules around cannabis "cannot be justified" and that possessing small quantities of the drug should be decriminalised.

The London mayor said that a new report, published by the independent London Drugs Commission (LDC), provides "a compelling, evidence-based case" for the government to consider the move. But what are the current laws, what are the proposed changes, and what's the difference between legalising and decriminalising? What are the current laws in the UK? Cannabis is a Class B drug and people found in possession can face a fine or imprisonment.

While using cannabis for recreational purposes is illegal, it is occasionally prescribed for people with multiple sclerosis, experiencing nausea as a side effect of chemotherapy or suffering rare, severe forms of epilepsy. When police catch someone in possession of cannabis, they have options as to what to do next.

They can issue a warning or an on-the-spot fine of up to £90, and can hand over the penalty without giving a formal warning or caution. If you're repeatedly found with cannabis, the penalty may increase to the maximum for possession: five years in prison and/or an unlimited fine.

People are rarely imprisoned for possession of cannabis, according to the LDC. The government says the penalty depends on where the offender and the drugs were found, their personal history including any previous drug offences, and "other aggravating or mitigating factors".

If the offender is under 18, the police can tell their parent or carer they've been caught with drugs. There are far more serious punishments for unlicensed dealing, production or trafficking of the drug, with those found guilty facing up to 14 years and/or an unlimited fine.

What does the mayor want to change? The LDC, which Sir Sadiq set up in 2022, has recommended that "natural" cannabis should be moved from the Misuse of Drugs Act (MDA) to the Psychoactive Substances Act (PSA). This would not be the same as fully legalising cannabis, but would mean cannabis possession for personal use would no longer be a criminal offence, regardless of whether or not the drug has been prescribed.

It would mean police stop-and-searches could not be deployed solely on suspicion of someone having it, and that they can only be carried out when someone is suspected of more serious cannabis offences such as supplying or trafficking. The LDC is not aiming to change the law on synthetic cannabis, which is much more potent and thought to pose a greater risk than natural cannabis.

What is the difference between decriminalisation and legalisation? Decriminalisation is not the same as legalisation. If the possession of cannabis were to be decriminalised, it would still be illegal to possess and use the drug.

However, it would mean that these actions would no longer carry the risk of criminal penalties. By comparison, legalising the drug would mean it is not against the law to possess or use, and there are no criminal penalties associated with it.

It would also mean the production, sale and consumption could be regulated by the government, for example with cannabis cafes and dispensaries and taxes on products. Why does the mayor want to change the law? The LDC's report was an examination of the nature and effectiveness of UK cannabis law and involved collecting evidence from more than 200 witnesses nationally and internationally.

It examined how the drug is policed around the world, and concluded that criminalising cannabis possession was "not fit for purpose" and that the law required "modification". Here is a summary of its rationale: • It said while cannabis can cause considerable harm to a minority of people who use it, the severity of possession charges was "disproportionately high".• It found police were more likely to search those from ethnic minorities for cannabis despite the fact they are statistically no more likely to be carrying it, damaging their relations with law enforcement.• It also said the change would mean that people who need cannabis for medicinal purposes but couldn't afford to get a private prescription wouldn't be penalised.• It said the change, while "not a perfect solution.