Labour is calling for the raw product for medicinal cannabis to be grown in New Zealand.

Labour MP Damien O'Connor says New Zealand lost out to Australia on a similar economic opportunity years ago and he doesn't want to see it happen again.

Tasmanian poppy farmers supply nearly half of the world's legal opiates that are used to make powerful painkillers like morphine and codeine.

The industry's one of the state's biggest employers and is estimated to be worth $100 million dollars a year.

"In the '70s NZ had the opportunity to grow poppies for medicinal purposes. We turned our back on that; Tasmania has been the beneficiary of that," Mr O'Connor says.

He says growing medicinal cannabis could also be a boost for New Zealand's economy and would create jobs.

"The opportunity to diversify our economy and the opportunity to grow high quality products for health is something that should be considered," he says.

Mr O'Connor supported a bid by Rose Renton to administer medicinal cannabis to her son Alex, who was suffering prolonged seizures in hospital.

Last year Mr O'Connor put forward a bill to give doctors and specialists the right to supply medicinal cannabis products to patients in need.

"Any cultivation of cannabis for medicinal purposes would have to be in a safe and secure environment," he says.

But the Government is having none of it.

"From what we see, the damage in Northland, we don't want to worsen that," Prime Minister Bill English says.

Labour says it wouldn't want to see widespread growing of cannabis for recreational use.

As for the dollar value of growing cannabis for medicinal use, Mr O'Connor told Newshub he couldn't even guess, but says it would depend on the export potential.