Sadiq Khan has voiced his support for the decriminalisation of possessing small amounts of natural cannabis, stating that the existing regulations are indefensible.

The Mayor of London referenced a report by the independent London Drugs Commission (LDC), released on Wednesday, which he believes presents a strong, evidence-based argument for decriminalisation, urging the Government to consider the change.

Established by Khan in 2022, the LDC, led by former lord chancellor Lord Charlie Falconer, concluded that current cannabis laws are disproportionate to the potential harm, following a global study of cannabis policing.

The commission also highlighted that cannabis policing disproportionately affects specific ethnic communities, straining relations between them and the police.

While stopping short of advocating full decriminalisation due to concerns about long-term public health impacts, Lord Falconer’s committee suggested moving “natural” cannabis from the Misuse of Drugs Act to the Psychoactive Substances Act.

This would effectively legalise possession of small quantities for personal use, while still prohibiting the import, manufacture, or distribution of the drug.

They also called for improved addiction services and greater education for young people on the dangers of cannabis.

Lord Falconer said: “Legalisation is not the answer. The criminal justice system response needs to focus only on the dealers and not the users.

“Those who suffer from the adverse effects of cannabis – which may be a small percentage of users but it is a high number of people – need reliable, consistent medical and other support. And there needs to be much more education on the risks of cannabis use.”

Under current laws, cannabis is a class B drug and those found in possession face a fine or imprisonment.

LDC deputy chairwoman Janet Hills, a former Metropolitan Police detective, said the report was “a driver for change in our community” and called for “a more balanced and compassionate approach to policing in our city”.

Responding to the report, Sir Sadiq said: “I’ve long been clear that we need fresh thinking on how to reduce the substantial harms associated with drug-related crime in our communities.

“The London Drugs Commission report makes a compelling, evidenced-based case for the decriminalisation of possession of small quantities of natural cannabis which the Government should consider.

“It says that the current sentencing for those caught in possession of natural cannabis cannot be justified given its relative harm and people’s experience of the justice system.

“We must recognise that better education, improved healthcare and more effective, equitable policing of cannabis use are long overdue.”

A Home Office spokesperson said: “We will continue to work with partners across health, policing and wider public services to drive down drug use, ensure more people receive timely treatment and support, and make our streets and communities safer.

“The government has no intention of reclassifying cannabis from a Class B substance under the Misuse of Drugs Act.”

Shadow home secretary Chris Philp said: “Possession of cannabis should not be decriminalised like this. We have seen some US and Canadian cities devastated by soft policies on addictive and harmful drugs – now Sadiq Khan wants to send London the same way.

“Cannabis is illegal for a reason. Cannabis is associated with anti-social behaviour and heavy use can lead to serious psychosis and severed mental health problems.

“US and Canadian cities which tried this approach have ended up as crime-ridden ghettos with stupefied addicts on the streets and law-abiding citizens frightened to go there.

“Sadiq Khan is more interested in politically correct posturing for the benefit of his left-wing friends than he is making London a safe and nice place.

“I completely oppose these plans. But with a weak Labour Government in power, there’s no telling how they will react. We must stop soft Sadiq.”