A Federal Court judge is expected to release a decision today on whether medical marijuana patients have the right to grow their own cannabis.

The constitutional challenge was launched by four British Columbia residents who argued that legislation introduced by the previous Conservative government violated their charter rights.

The Marijuana for Medical Purposes Regulations were introduced in 2013 and required patients to buy cannabis from licensed producers instead of growing their own.

Sarah Stuive, biological control consultant, checks for bugs at Bedrocan Canada, a medical marijuana facility, in Toronto in August 2015. (Darren Calabrese/Canadian Press)

An injunction has allowed those who already held licences to continue growing marijuana until the Federal Court decision, which is set to have national impact on medical cannabis users and the new Liberal government.

The Liberals have committed to regulating and legalizing recreational marijuana but have said little about their plans for medical marijuana since being elected.

Neil Allard, who launched the case with three others, said he expects to bring it to the Federal Court of Appeal if today's decision is not in their favour.

"If we don't win our rights to grow our own cannabis at home, you can pretty much guarantee that there's going to be an appeal," he said.

Injunction protected plants

Lawyer Kirk Tousaw said the Crown has argued the injunction allowing licence holders to continue growing their own should immediately end if the judge upholds the law.

Tousaw said he has asked the judge to give people time to remove their plants.

"If we lose, we will appeal, and we will attempt to, as quickly as possible, get a hearing on either continuation of the injunction issued by the trial court or a new injunction," he said.

"Obviously, it's going to be incredibly difficult for patients who have been protected by the injunction to be criminalized overnight, and I think that that's fundamentally unfair to them."

Judge Michael Phelan heard the case between February and May 2015 in Vancouver's Federal Court.

Federal government lawyers argued that the new regime ensures patients have a supply of safe medical marijuana while protecting the public from the potential ills of grow-operations in patients' homes.

But the lead counsel for the plaintiffs, John Conroy, told court that the legislation has robbed patients of affordable access to medicine. Some people were left with no choice but to run afoul of the law, he argued, either by continuing to grow their own or by purchasing on the black market.

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