Brits would only be allowed to purchase the drug in fully-licensed shops, similar to the system currently used in a number of US states. 

The party predicts the policy could raise up to £1 billion in tax and would relieve the pressure currently felt by the NHS, prisons, and emergency services. They add that it would make it easier for people to get hold of the drug for medicinal purposes and would reduce crime by forcing drug dealers off the street. 

“What we currently do is bad for health and mental health,” Huppert, who is standing to win back the Cambridge seat he lost in 2015, told BuzzFeed. “The market is run by criminal gangs and they have no interest in public health – the system is causing huge amounts of harm.

“The prohibitionist approach costs a huge amount of money, means we criminalise a large amount of people and increases the harm,” he added. “We spend a lot of money making people’s lives worse. That cannot be correct.”

The former MP said a Lib Dem government would create an independent regulatory body for the cannabis market in order to ensure cannabis sold legally in Britain contained low levels of THC, the chemical most responsible most of marijuana’s adverse psychological effects.

“There are two components in cannabis,” Huppert explained

“One is the potent active form. And one is protective and prevents harm. Criminal gangs have bred strains which don’t have the protective element, so skunk causes much more harm than marijuana used to do. In the same way we regulate the alcohol content of a drink, you can regulate the strength.”