The mayor of London is to launch a review examining the feasibility of decriminalising cannabis as part of a new approach to tackling drug-related crime. Should he be re-elected on 6 May, Sadiq Khan said he would set up an independent London drugs commission to examine the potential health, economic and criminal justice benefits of decriminalising the class-B drug. Khan believes there is widespread public support for a more relaxed approach to decriminalisation, citing polls showing more than half of the UK – and nearly two-thirds of those in the capital – support legalising cannabis for adult recreational use. Although he has ruled out the decriminalisation of class-A drugs such as heroin and cocaine, Khan is willing to consider supporting changes to the legal status of cannabis if that is what the commission concludes. Any actual changes in the law regarding cannabis would, however, fall to the government. “It will be for the commission to look at the evidence in the round, but nothing is off the table in the context of what is best for public health and keeping Londoners safe,” said a source close to the mayor. The announcement of the proposal to set up a London drugs commission is expected to be part of Khan’s mayoral election manifesto, published on Tuesday. Khan will say fresh ideas are needed to counter the illegal drugs trade, which is damaging both Londoners’ health and their communities, as well as fuelling an increase in organised and violent crime. Too many young people are criminalised for use of of drugs, he believes. The illegal drug trade in the UK is estimated to cost society £19bn per year, according to the mayor’s office. About 41,900 people across England and Wales were charged with drug-related offences last year. Legalising and regulating the sale of cannabis would raise at least £1bn in taxes for the Treasury, according to some estimates. But formally adopting such a position could put him out of step with the Labour leader, who recently said he was opposed to decriminalisation. The current drugs laws were “roughly right”, Keir Starmer told Sky News, though he added that there was “always room for a grown-up debate about how we deal with these cases”. The London drug commission, which would be comprised of independent experts from criminal justice, public health, politics, community relations and academia, would examine how countries around the world have tackled problems with drug use and addiction. This is likely to include looking at evidence from Portugal, where possession and consumption of drugs have been decriminalised since 2001 as part of a wider approach to drugs, including improved treatment programmes and better prevention, education and social support services. It is also likely to consider the experiences of Canada, Uruguay and several US states, where cannabis for recreational use has been legalised. Private use of cannabis is allowed in Spain, while Dutch coffee shops have long sold marijuana. The commission would collate the latest evidence on the effectiveness of UK drug laws, police enforcement and addiction support services. It would report to the mayor with recommendations for City Hall, the government, the police, the criminal justice system, and NHS and treatment services. Although Khan does not have the powers to introduce new laws, he believes that should the commission recommend decriminalisation of cannabis, a mayoral endorsement would give it a boost. Khan, who has in the past called for “an evidence-based conversation” around cannabis, will say: “It’s time for fresh ideas about how to reduce the harms drugs and drug-related crimes cause to individuals, families and communities. “The commission will make recommendations focusing on the most effective laws to tackle crime, protect Londoners’ health, and reduce the huge damage that illegal drugs, including cannabis, cause to our communities and society.” In 2019 the cross-party Commons health committee called for the government to consult on the decriminalisation of drug possession for personal use. It said taking a health-based approach would benefit users and reduce harm and costs to the wider community. The Survation survey cited by the mayor’s office, published in July 2019, found that 63% of London residents backed the legalisation and regulation of cannabis, while just 19% opposed the idea. Across the UK as a whole, 47% backed legalisation, with 30% against. • This article was amended on 6 April 2021 so the main heading – which spoke of cannabis legalisation – better reflected the text, which gives decriminalisation as the subject of the mayoral review.