Canada has become the first country in the world to legalise the widespread medicinal use of marijuana, allowing people suffering from chronic illnesses to grow and smoke the drug.

The regulations introduced yesterday will allow thousands of people to harvest the plant themselves or name a third-party provider to grow it for them. The Canadian government is overseeing production of its own supply in a former mine in the province of Manitoba.

Paul Lewin, of Canada's Marijuana Party, said: "This is a good thing, although it does not go far enough. But the reason this is happening is that the government was forced to do so by the courts. It is not as though our government is any more enlightened than anyone else's."

The man who forced the change is Terrance Parker, a 44-year-old epileptic who says that the drug is the only way to control his seizures. He smokes up to four joints a day. In 1996 Mr Parker was arrested for possession, cultivation and trafficking after police raided his home and seized more than 70 marijuana plants. Mr Parker argued that his constitutional rights were being abused and a judge agreed.

Last year, the Ontario Court of Appeal upheld the court's ruling, paving the way for other sufferers to grow and use the drug. In his ruling, Judge Marc Rosenberg said: "I have concluded that the trial judge was right in finding that Parker needs marijuana to control the symptoms of his epilepsy.

"Forcing Parker to choose between his health and imprisonment violates his right to liberty and security of the person," the judge said.

Canada's position is in stark contrast to its neighbour, the United States. While eight states there have moved some way towards permitting the medicinal use of marijuana, the US Supreme Court ruled earlier this year that there were no circumstances when its use was permitted. This raises the farcical proposition of someone permitted by their state to use the drug being arrested by federal officials.

Chuck Thomas, of the Washington-based Marijuana Policy Project, said: "We're envious of Canadians having the luxury of complaining about the minutiae of the programme. It seems like a reasonable system."

In Britain, trials of the medicinal use of marijuana have been going on for the past two years. Earlier this year the trials were extended to include thousands of people suffering from chronic pain.

Campaigners in Canada say there is still too much bureaucracy attached to the new regulations. Use of the drug is permitted only for the terminally ill with a prognosis of death within one year, those with symptoms associated with a specific, serious condition and those with other illnesses who have statements from two doctors saying conventional treatments have not worked. People with severe arthritis, cancer, HIV/Aids and multiple sclerosis will also be eligible.

But there are signs that the regulations could be eased. More than 500 applications for use of the drug are pending and many more are expected. The Canadian Justice Minister, Anne McLellan, has said the issue of decriminalising the drug should be explored. To be able to fulfil its legal obligations to sufferers, the Canadian government has awarded a $3.5m (£2.5m) contract to Prairie Plant Systems to grow and harvest marijuana in the former mining town of Flin Flon, Manitoba, 200 miles north of the American border. The first harvest is expected this autumn.

One shop in town has already sold more than 6,000 T-shirts bearing the legend, "Flin Flon – marijuana-growing capital of Canada".