STEVEN Agnew has become the first assembly member to call for cannabis to be decriminalised.
The North Down MLA told The Irish News that the Class B drug should sold to over-18s and taxed like alcohol and tobacco.
"It is our policy to have legal regulation of cannabis," he said.
"It’s not about saying cannabis is a wonder drug – like any drugs it has harmful effects and I think it should be properly regulated and taxed."
But Mr Agnew said that while the legalisation of cannabis was Green Party policy it would not be a manifesto pledge for the forthcoming assembly election because drugs laws are not devolved.
Possession of cannabis is illegal in the north under the UK-wide Misuse of Drugs Act 1971.
The Green leader, who previously taught community drugs awareness courses, said cannabis use should also be permitted for the treatment of illnesses. He said assessing the harmfulness of the drug was "a decision for a doctor rather than a politician".
Mr Agnew said the proscription of cannabis led to people who were otherwise law abiding being criminalised.
"People often talk about cannabis being a gateway drug but it’s not a gateway to harder drugs, it’s a gateway to criminality," he said. "The biggest problem is that for many people who are law abiding it’s their first criminal act and their first link to criminal gangs."
He said cannabis supply should be "taken out of the hands of paramilitaries".
