A candidate to become the next mayor of London today called for cannabis to be legalised.

Lib-Dem Siobhan Benita said decriminalising the Class-B drug would help to tackle the capital’s violent crime epidemic.

Her intervention follows an Evening Standard investigation into reforming the laws on cannabis. We found that 63 per cent of Londoners back its legalisation for adult recreational use.

In an interview with the Standard, Ms Benita also revealed plans to revive the Lib Dems’ “Bollocks to Brexit” slogan to court voters for City Hall next year.

The Lib Dems topped the polls in London in May’s Euro elections, taking 27.2 per cent of the vote and electing three MEPs. Labour got 23.9 per cent while the Conservatives plummeted to 7.8 per cent.

Ms Benita believes Labour’s confused stance on Brexit and its response to allegations of anti-Semitism will reduce support for incumbent Sadiq Khan, despite his opposition to Brexit and support for Jewish Londoners.

She accused Mr Khan of failing to get a grip on the underlying causes of violence and said he was too focused on blaming the Government for a lack of police.

Ms Benita said decriminalising cannabis would allow police to concentrate on more serious crimes. There have been 89 homicides in London so far this year. She said: “We don’t tackle knife crime only with policing, we tackle it with early intervention. This is about leadership and bringing people together. That is where Sadiq has spectacularly failed.” She said there is a link between illegal drugs and serious violence, so legalising and regulating the market for cannabis would remove power from gangs selling the drug.

Ms Benita said: “I would like to go further [than decriminalisation] and legalise it. One of the key reasons for doing that is so we could regulate the strength and control the quality. That is safer for users and removes power from criminal gangs.”

She pointed to cannabis laws in the US and Canada as examples the UK could follow. Recreational use is legal in Canada and 11 US states, and is decriminalised in a further 15. In the UK, possession can result in five years in prison and 14 years for supply and production.

“We should have a much more supportive approach to people who are addicted to drugs, rather than putting them through the criminal justice system,” she added.

Asked whether she had taken drugs, Ms Benita replied: “I can honestly say, and I’m quite embarrassed about it as it makes me sound quite nerdy, I have never taken drugs in my life. I have only ever smoked one cigarette.”

The former Whitehall civil servant, 47, stood as an independent in the 2012 mayoral election and joined the Lib Dems in 2016 after the EU referendum.

She hopes Conservative voters will see her rather than Tory candidate Shaun Bailey, a Brexiteer, as the best way to defeat Mr Khan. Ms Benita would have to be one of the top two candidates from the first round of voting to stay in the running. She said her priorities would be knife crime and serious violence, the environment and air quality, “homes that people can afford” rather than “affordable homes”, and Brexit.