The more harmful, dangerous and addictive a drug is the more important that its availability should be legally regulated, otherwise, inevitably, a criminal market is created with massive consequential health and social harms.

In the UK, before the Misuse of Drugs Act was introduced in 1971, we had around 3,000 problematic drug users. We now have 350,000. Yet successive governments carry on in the same direction.

The vested interests of Big Booze have been supported and encouraged by weak politicians, leading to lighter and lighter regulation of the most dangerous drug of all. Meanwhile, relatively harmless and beneficial substances like cannabis have been abandoned to street dealers and organised crime, blighting communities and involving children in both dealing and use – just as happened with alcohol prohibition in the US.

All the evidence is before us and the most effective policies for reducing harm from drugs are very clear. What…