Is it time for London to legalise cannabis?

Basel is orderly, prosperous and bourgeois. It is hosting the next dressage World Cup, the faces of bankers grace advertisements at tram stops and commuters are encouraged to make donations to help protect artisanal alpine beekeeping. The city is perhaps an unlikely place to legalise recreational cannabis. But it has been sold legally here in a dozen high street pharmacies and a dispensary — and across Switzerland’s biggest cities — for the past three years as part of a legalisation pilot project. The nationwide effort to study different models of regulation is not premised on cannabis being entirely harmless. Rather, it asks whether those harms are better managed by the state than left to an illegal market.

In London, however, the authorities still spend vast sums policing a lucrative cannabis market that remains in criminal hands. Across the capital, almost one in 10 adults are cannabis consumers, the highest proportion of any British region, and polling has shown two-thirds of Londoners favour either legalising or decriminalising cannabis.

Last year, an independent London Drugs Commission report commissioned by the mayor, Lord Sadiq Khan, concluded that the “continuation of the law as it currently stands cannot be justified”. The commission recommended the partial decriminalisation of cannabis and noted that prohibition “does little to prevent access to the drug”. Cannabis policing also falls disproportionately on black communities, it warned, creating a “pervasive sense of persecution” with “damaging, long-lasting consequences”. Yet despite pro-reform Khan posing between rows of cannabis plants at a factory in Los Angeles in 2022, the commission stopped short of recommending legalisation. The “extent of harms, particularly with respect to public health, as well as personal and societal costs, take longer to emerge and are not yet well understood”, it said.

Cannabis shop in Lucerne, Switzerland

Switzerland is intending to answer precisely those questions and could be the key to change closer to home in our capital. Basel’s suburban dispensary, Grashaus, is discreetly situated on a quiet residential street between a restaurant and a funeral home. Inside its frosted windows, pastel furniture, pale wood shelving and house plants make it look more like a Scandinavian lifestyle boutique. The tasteful decor reflects cannabis’ increasingly mainstream place in modern culture. For many its widespread appeal is straightforward: relaxation, enhanced appreciation of music or food, or simply a different way of unwinding at the end of the day. Others self-medicate with cannabis instead of using pharmaceutical drugs.

Neuroscience student Esme is one of almost 2,000 participants in the Grashaus trial in Basel-Landschaft. The 21-year-old says that before she started consuming cannabis she had “debilitating” anxiety and suffered from insomnia. But now her panic attacks are far less common, and she can sleep much more easily. “It has helped a lot,” she says, without wishing to use her surname for privacy reasons.

“People are going to buy cannabis anyway, so it’s better to do it in a safe setting”

Esme

Without the regulated study and her membership card, she would instead be buying on the street from a dealer — a prospect she is particularly wary of as a trans woman. Equally, she prefers the organic cannabis at Grashaus to the illegal-market weed of wildly varying strengths. “You never really know who you’re meeting up with,” Esme says. “You’re just hitting up whoever on social media. People are going to buy cannabis anyway, so it’s better to do it in a safe setting.”

In 2013, Switzerland decriminalised possession of up to 10 grams, and its university-affiliated pilots encompass dozens of dispensaries, social clubs where members can consume, high-street pharmacies dispensing cannabis alongside prescription drugs, and non-profit stores run by the state.

Basel approach is cautious

“Cannabis isn’t for everyone, and our staff say so openly,” says Adele Hollmann, the scientific affairs manager at Sanity Group, the company behind Grashaus. “But people use it whether it’s legal or not. Switzerland has accepted that reality and is testing which model works best before deciding how to regulate it. In the meantime, adults who choose to use it get quality-controlled products and honest information about what they’re consuming.”

The early Swiss studies mostly involve pre-existing cannabis consumers only and are not necessarily representative of a fully legal market, but the findings are intriguing. Initial data suggests that legalisation may even reduce cannabis use. Data from Grashaus also suggests that people will mostly purchase from legal sources if they have the option. Four-in-five participants also say staff are a useful source of advice on lower-risk use, with tobacco consumption with cannabis declining significantly.

Experts, scientists and politicians are now calling for London to follow the Swiss and establish its own pilot scheme to assess the benefits and risks of a regulated cannabis market. Legalisation could be a boon for tax revenues, likely raising billions over a decade, according to one nationwide projection. Nor would London be venturing entirely into the unknown. Canada legalised recreational cannabis in 2018, while half of US states have legalised it for adult use. In 2024, Germany became the ninth country to legalise.

Experts said cannabis increases the risk of paranoia (Alamy/PA)

Alamy/PA

But Switzerland is taking a more cautious approach. At Grashaus, Hollmann says that thorough screening prevents access for vulnerable people. Each pilot involves a recognised independent research institute, including top universities, and must be authorised by the federal health office. “We only take adults who already use cannabis,” she says, explaining that each person has to provide a urine test. “We’re not here to create new consumers.” Participants can be referred to doctors if problems arise. So far, no psychiatric incidents related to Grashaus have been reported, according to Hollmann. “We have a range of products, including lower-strength options,” she says. “Everything in the trial has to be grown here in Switzerland to organic standards. Every batch is then checked by a certified lab, with nothing above 20 per cent THC permitted to be sold.”

The experiment is also deliberately insulated from some of the commercial pressures seen elsewhere: shops cannot advertise and cannabis can only be sold to registered participants.

“We should not simply create a cannabis equivalent of the alcohol industry”

Dr Rayyan Zafar

Dr Rayyan Zafar, a neuropsychopharmacologist at Imperial College London, says that London should implement “a carefully designed legalisation pilot because prohibition has not stopped people using it and has made quality, potency and levels of education harder to control.” Zafar warns against adopting the commercial models of some US states and Canadian provinces. “We should not simply create a cannabis equivalent of the alcohol industry,” says Zafar, also a senior researcher at Drug Science, an independent scientific advisory committee. “There should be strong safeguards for vulnerable people across medical and recreational models.”

About 75,000 people in the UK access medical cannabis, legal since 2018, through private clinics — with many reporting significant benefits, and a relatively small number complaining of side effects. Zafar points to the contrast with alcohol, which is associated with “enormous health and social harms”.

Alcohol is implicated in around two-fifths of violent crime and around one-in-seven road deaths. There are more than a million alcohol-related hospital admissions per year in England alone, with more than 20,000 deaths.

In Britain’s remarkably resilient illegal cannabis market, producers face no enforceable requirements to limit potency or ensure product safety, despite growing concerns about increasingly strong cannabis, and synthetic versions. “The billions of pounds generated annually from the UK illegal drug trade are laundered in the UK and overseas, fuelling further criminality,” says the National Crime Agency’s 2026 strategic assessment of organised crime. “Firearms are used by [organised crime groups] to protect their illicit drugs business, enforce debts and intimidate rivals.”

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Thirteen police forces in England and Wales already have diversion schemes for drug possession, including cannabis, to divert people caught with personal amounts away from the backlogged courts. But while the Metropolitan Police now say arrest should be a “last resort” for simple cannabis possession, they continue to use stop-and-search to detect drug offences and devote substantial resources to disrupting the supply and cultivation of cannabis. “In many urban areas, any officer who makes an arrest for cannabis is not appreciated by his colleagues, wasting time away from the streets,” says former undercover drugs detective Neil Woods, the chair of Law Enforcement Action Partnership UK, which campaigns for drug legalisation. “It will ultimately make no difference to the amount of illegal cannabis on the market.”

Labour backbencher Bell Ribeiro-Addy MP says the UK should prioritise public health.

“Our drug policy has failed,” she says. “Countries like Switzerland are showing us a better way forward, centred on harm reduction. “On cannabis, there is an increasing body of evidence pointing towards legalisation as the best means of protecting communities and reducing the harms associated with use.”

Taxpayers are losing out under the current system, says Georgia Glick, founder of cannabis consultancy firm Tocar Strategic Advisors.

“We could potentially generate over a billion pounds per year in tax revenue”

Georgia Glick

“We could potentially generate over a billion pounds per year in tax revenue, save almost £300 million in criminal justice costs and create more than 15,000 jobs,” she says, citing modelling by Transform Drug Policy Foundation, a charity that has been campaigning for a Swiss-style pilot. “After EU law complicated Germany’s efforts to legalise cannabis, London and the UK have a unique opportunity to learn from other countries’ mistakes and create a system that works for everyone and boosts the economy.”

But a pilot, she says, which would require support from Westminster, “is how we start testing those numbers with real UK data”.

Controlling the supply chain

Back at Grashaus in Basel, another participant has arrived to purchase cannabis. Vincent, a 32-year-old afterschool teacher, says that he only consumes once his day is complete.

“Of course, if you’re driving, working or trying to teach children, you shouldn’t be high,” he says, without wishing to use his surname for professional reasons. “But there are scenarios where, for many, it just makes you live in the moment and enjoy yourself more.”

While nationwide legalisation remains under political debate, Switzerland’s experiment continues to expand, and Grashaus is soon opening a new larger pilot store subject to final approvals. Vincent, meanwhile, hopes he never has to buy cannabis of unknown origin, quality or character from the illegal market again. “Imagine if you had to get alcohol from a dealer and you wanted wine but they gave you off-brand vodka,” he says, invoking memories of America’s disastrous alcohol prohibition experiment that fostered the rise of gangsters such as Al Capone. “Why wouldn’t you want to control the supply chain,” Vincent adds, “rather than let it be destroyed by the black market?”