A new poll suggests more than 60 percent of New Zealanders want a cannabis law change.
The New Zealand Drug Foundation, which commissioned the survey, said it was the first such poll to show a majority backing the loosening of rules on the personal use of marijuana.
Of 1029 participants, 64 percent thought possessing a small amount of cannabis for personal use should be either legal (33 percent) or decriminalised (31 percent). A minority of 34 percent supported maintaining prohibition of personal use and possession of cannabis.
A Drug Foundation spokesperson said previous similar polls had shown the opposite or a 50/50 split.
Executive director Ross Bell said the support for change was much higher than he anticipated and showed the public wanted change even if lawmakers did not.
"The voters have better understood this issue, that there are alternatives, that the current approach - the 40 year approach - that we've taken hasn't done anything to arrest New Zealand's cannabis use and maybe it's time to try something new," Mr Bell told Morning Report.
"We're acutely aware of the health problems associated with cannabis - we've been trying to reduce those harms for a long time - but those harms exist under the current approach.
"If we flip it around, remove the criminal justice approach, put in a health approach, then we might actually grow up in New Zealand and start dealing with cannabis in the way that it should always be dealt with."
Mr Bell said politicians should now be able to proceed with cautious reform without fear of a voter backlash.
Prime Minister John Key admitted the laws around cannabis were not always working perfectly - but said liberalisation of drug laws was not on the government's agenda.
"It's been my longstanding view really that one of the things that Parliament does is send a message to people about activity we want to see or not want to see.
"In the case of drugs I think if we as a Parliament were to decriminalise then one of the message we'd be sending is that increased drug use is okay."
Mr Key said police did not generally prosecute people using cannabis for medical reasons, and used their judgement on personal use.
"There are always tolerances and margins - it's for the police to determine that."
The poll also showed 52 percent of participants wanted to see the liberalisation of personal growing of cannabis, and 66 percent thought it should be legal for those with a terminal illness to use the drug.
Rose Renton fought to be able to use medical cannabis for her late son Alex, who became the first person in New Zealand to be granted an exemption for the use of cannabis to treat his epileptic seizures.
She said campaigners were not asking for recreational use of cannabis but for medicine.
Ms Renton said Mr Key's stand was outdated. "National as a democratic government must listen to its people."
Helen Kelly, former Council of Trade Unions president, has terminal cancer. She told Morning Report the pain control provided by a small amount of cannabis had been a revelation to her.
"I've been surprised at how I can take such a small amount in the evenings and survive the whole night relatively comfortably, and not have to take a whole lot of morphine, not have to take a whole lot of really zonking-out drugs, and then wake up and during the day manage that pain. There's nothing else like it."
Medicinal marijuana gets Labour's support
Labour Party leader Andrew Little said cannabis should only be available for medicinal purposes and not legalised for general use.
"There are real health risks with broader decriminalisation," he said.
"The scientific and medical evidence I've seen says that most of the cannabis available in New Zealand has high THC content and for still developing brains, that poses health risks. And finding a formula for decriminalisation that means you could mitigate those health risks, would be extraordinary difficult."
Mr Little would not rule out a referendum on the topic.
"It would be arrogant of me to say no, that should never be considered, that would be the wrong thing to do. There may be conditions, a greater level of public awareness or public education in which, that may be the most sensible thing to do," he said.
"What I do think we need to have in terms of any public debate, is good scientific, medical information. It can't just be based on emotion and what kind of feels right to some people."
However, Mr Little said decriminalising cannabis was not high on his party's agenda and it was more focussed on the housing crisis and education.
US, Canada law change having an effect
The Drug Foundation's Ross Bell said other factors in changing attitudes were recent debates around medical marijuana, and the law reform taking place in Canada and some US states.
Four US states have recently legalised cannabis through citizens-initiated ballots.
Massey University drug researcher Chris Wilkins said New Zealand was getting to the point where a referendum would be appropriate.
"But the really important thing here is if we go down the referendum track is that people are aware of all the different policy options that are out there. The worst case scenario is we just switch on to a commercial-driven market."
Mr Wilkins said another interesting aspect of the poll was the result by party affiliation, showing 55 percent of National party voters surveyed were least in favour of any kind of change.
Associate Health Minister Peter Dunne made no comment on the poll. The nationwide survey was carried out last month and earlier this month by Curia Market Research and has a margin of error of three percent.