Sadiq Khan is to launch a review examining the feasibility of decriminalising cannabis as part of a new approach to tackling drug-related crime in London.
The Labour mayor said he would set up an independent commission to examine the potential health, economic and criminal justice benefits of legalising the class-B drug if he is re-elected in May.
Polls show more than half of the UK – and nearly two-thirds of those in the capital – support making cannabis legal for adult recreational use.
Mr Khan ruled out the decriminalisation of class-A drugs such as heroin and cocaine.
But he is willing to consider supporting changes to the legal status of cannabis if that is what the commission concludes.
A source close to the mayor told the Guardian: ‘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.’