Green Party leader James Shaw said that legalising cannabis had been party policy for 20 years, and the use of the substance should be a health issue, not a criminal justice issue.
Now that the Green Party has joined a coalition with Labour and NZ First, the referendum is back on the agenda.
"The prohibition model hasn't work, plus it puts the entire trade into the hands of gangs," Shaw said.
"If you had a regulated market, the same way we do with alcohol and tobacco, you can control the price, advertising, point of sale, quality, and run full public health education campaigns."
New Zealand First supports a referendum on the decriminalisation of cannabis.
The Greens want to remove penalties for anyone with a terminal illness, chronic or debilitating conditions who grows, possesses and uses cannabis products for therapeutic purposes as long as they have the support of an authorised medical practitioner.
Herald readers commenting on the poll on Facebook said, for the most part, that they would agree with medical cannabis being legalised.
Some, however, worry about the consequences of making cannabis more readily available and want to keep it illegal.
And some readers think it could be legalised, but under strict conditions.