Public support for cannabis law reform has soared in the past year especially for medicinal use of cannabis, a poll commissioned by the New Zealand Drug Foundation has found.
Support for personal possession and growing has increased too but there is no great appetite to commercialise cannabis by selling it from stores.
Advocates of cannabis reform say the results show the laws are now out of touch with public opinion.
And they say the poll should give MPs heart as they consider a bill before the health committee to allow medicinal cannabis for pain relief in terminal conditions.
Separately the Government is planning a referendum on personal use before or at the next election.
Support to decriminalise or legalise cannabis for the use of pain relief has increased from 78 per cent last year to 87 per cent this year in what has become an annual survey.
Using cannabis for pain relief for terminal conditions is even higher, at 89 per cent.
Support for personal possession is up to 67 per cent from 65 per cent and support for personal growing of cannabis is up to 61 per cent from 55 per cent.
There is far less support for selling cannabis as a retail product from a store, only 38 per cent, although that is up from 34 per cent last year.
While the actual question to be asked in the referendum has not yet been decided, the poll also canvassed opinion on a referendum "seeking to legalise the sale of cannabis" and the results were split at 49 per cent for and 47 per cent against.
Over the three years that the poll has been conducted, support for personal use and for pain relief has risen among all political hues.
Not surprisingly 100 per cent of Green Party voters support the use of cannabis for pain relief (88 per cent last year), 91 per cent of Labour supporters (up from 78 per cent), 86 per cent of New Zealand First supporters (up from 77 per cent) and 80 per cent of National (up from 78 per cent).
The results suggest that Auckland is more conservative on the question of personal possession than anywhere else in the country with only 56 per cent supporting possession of cannabis for personal use compared to 82 per cent in Wellington, 67 per cent in Christchurch, 68 per cent in provincial cities and towns, and 77 per cent in rural areas.
Drug Foundation executive director Ross Bell said MPs considering cannabis reforms should take note of the poll.
"If Parliament is worried about levels of political support they only need to look at this poll to see there has been a huge shift in support for medical cannabis, not just for people with a terminal illness but for people in pain as well.
"Members of that select committee need to think very carefully about that when they write their report."
What is important is that before the referendum takes place, there is a good information campaign and people get good information about the issues.
Bell also thought support for a referendum question on the sale of cannabis was quite high, given that the public education campaign had not begun.
Bell said the Drug Foundation's model law would include decriminalisation of all drugs, increased spending on treatment and prevention, and a regulated market for cannabis.
"Our drug law isn't working. Our drug law is very old, 1975 law. We have very high levels of cannabis use so the law isn't preventing use and instead is creating a whole lot of extra harm through criminalising people, and specifically criminalising young New Zealanders and Maori.
"It is time to do something differently and I think the public is ready for that."
Green MP Chloe Swarbrick said the increase in support for medical use of nearly 10 points in a year showed that views could shift with debate informed by evidence.
"What we are seeing is an openness to the argument and to the evidence but also, now more than ever, it would appear that our laws are out of touch with what the New Zealand public thinks they should be."
A private member's bill in Swarbrick's name which would have allowed cannabis use for people with debilitating conditions was voted down in January at its first reading – and was opposed by all New Zealand First and National MPs.
A more conservative bill restricting medicinal use to people with a terminal condition was introduced by Health Minister David Clark and a report from the health select committee is expected soon.
MPs are likely to be given a conscience vote when it gets back to the House.
I am very unlikely to support decriminalisation for recreational use because as a prosecutor I have seen the mental health implication and the debilitating effect it has had on parts of the community, particularly in the Eastern Bay of Plenty.
Swarbrick hoped the health committee, after hearing extensive submissions, would recommend that the Clark bill be broadened to include people in pain, not just with terminal conditions.
Justice Minister Andrew Little who is responsible for the cannabis referendum said the poll showed incremental support for liberalisation "and that is without the benefit of any major information campaign about it".
He said consultations among Labour, New Zealand First and the Greens was underway about the referendum and its wording and he expected to take a paper to cabinet in two to three months.
The poll was useful to have but the Government was committed to a referendum and the processes leading up to it were independent of any poll.
"What is important is that before the referendum takes place, there is a good information campaign and people get good information about the issues."
National Party leader Simon Bridges said he was surprised that support for medicinal cannabis use was so high.
National was in favour of the David Clark bill in principle but it would need appropriate safeguards as any other pain relief drug would.
On the issues of personal use around the referendum, that would be a conscience vote.
"I am very unlikely to support decriminalisation for recreational use because as a prosecutor I have seen the mental health implication and the debilitating effect it has had on parts of the community, particularly in the Eastern Bay of Plenty."
• The poll of 943 eligible voters was conducted between July 2–17 by Curia Market Research. It has a margin of error of plus or minus 3.2 per cent.