Moves are afoot by a group of senior citizens to decriminalise cannabis so people can grow small amounts to use for health purposes.

However the Government is unlikely to lend it any support.

Health Minister Jonathan Coleman is on the record as opposing decriminalisation and Justice Minister Amy Adams is equally cool.

When the issue came up last year her view was that there was very little support for change when it was last looked at.

The Prime Minister is also on the record as opposing decriminalisation.

Otamatea branch Grey Power President Beverley Aldridge is leading the campaign with her petition on the issue to be considered by parliament's Justice and Electoral Committee this week.

She said the matter came up in local meetings where they discussed how people were dying in pain and weren't able to be treated for other chronic conditions such as colitis.

"So we all decided to do some research and we found this wonderful medicinal plant cannabis, which we'd been misinformed on how bad it was, when actually there are so many benefits from using it."

Ms Aldridge said the drug has been unfairly demonised.

"I believe that the current prohibition of cannabis is enforced like the witch hunts were in the Middle Ages."

New Zealand First leader Winston Peters is down as the MP presenting the petition to parliament - not because he endorses it, but because it's a obligation he has to the petitioner who lives in his local electorate.

"It's something that I think the select committee should look at and let's have the evidence from all sides of the argument or debate and then we'll make up our mind," he said.

Labour MP Jacinda Ardern said while her party's pushing for better access to medicinal grade cannabis-based treatments, the petition is a step beyond what Labour's seeking.

"It goes further than certainly the Member's Bill that we've had prepared in Damien O'Connor's name who is the promoter of that bill."

Ms Aldridge believes public opinion's on her side, citing a UMR poll which had 76 per cent agreement for cannabis being legalised.