Medicinal marijuana: If it's effective Peter Dunne will back it

New Zealanders increasingly favour legalising the medical use of marijuana, a ONE News Colmar Brunton poll shows.

Support has grown more than 10% since ONE News last tested the question 12 years ago but very few voters think it should be decriminalised completely.

Currently 48 New Zealanders are legally allowed to use Sativex which contains cannabis derivatives and the Associate Health Minister supports such products.

"If those products are shown as a result of the normal testing programme to be fit for purpose then we will permit them to be made available in New Zealand," Peter Dunne says.

A group called United in Compassion which wants more trials of medicinal marijuana has met with Mr Dunne to discuss the issue and the ONE News Colmar Brunton poll also backs them.

Nearly half (47%) say marijuana should be legal for medical cases while 21% say it should remain illegal. But just 9% believe marijuana should be legalised for recreational use with 21% saying possession of a small amount should only incur a fine and no criminal conviction.

"I think fundamentally people have some real compassion for people who are suffering who could benefit from the medicinal properties of cannabis," Drug Foundation chief executive Ross Bell says.

The Government is currently reviewing national drug policy and laws and while Mr Dunne won't support legalising recreational use he is taking a wait and see approach on medicinal marijuana.

He wants proof of extensive, approved testing processes and says it depends entirely on whether it's effective.

"I don't think the notion of just puffing a few joints in your backyard to ease your pain is credible."