OTTAWA - The federal government is poised to tighten the rules on medical marijuana so that only licensed private operators are allowed to grow it, The Canadian Press has learned.

Sources say Health Minister Leona Aglukkaq wants to take individuals and Health Canada out of the business of growing pot.

Instead, she wants to tender licences to the private sector to produce marijuana in a way that is similar to how conventional drugs are produced -- by companies, under tightly regulated conditions.

The move is a response to complaints from mayors, police and firefighters -- mainly in British Columbia -- who say sanctioned growers are abusing their permits and often growing far more than they need.

Just this month, for example, police in Maple Ridge, B.C., found more than 1,400 plants at a site that was permitted to grow just 220.

"There are significant issues with people cultivating above the limit," said Eric Nash, a legal cannabis expert on Vancouver Island.

Police have also complained that even growers who stick to their limit attract criminals to their sites, creating a neighbourhood safety risk.

And municipal officials are concerned about the fire hazard from chemicals and faulty wiring that may be used in growing the plants.

Indeed, B.C., mayors have been asking Health Canada to change the medical marijuana rules to require municipal permits.

They say licences to cultivate medical marijuana have been given out without informing local authorities or requiring proper building permits. Local emergency responders aren't able to tell the difference between legal and illegal grow-ops.

The mayors took their campaign to the Federation of Canadian Municipalities earlier this month and won national support, with the organization formally asking Ottawa to clamp down.

Aglukkaq is expected to go further than requested by the mayors, but not right away. She intends to phase in the changes, but also to consult on the technicalities of how best to implement them.

"At this point in time, we will be looking to consult on changes that we hope will balance patient access with safety and security," said Aglukkaq's spokesman, Steve Outhouse.

For now, there are three legal ways to grow medical marijuana. A person who gets a doctor's prescription will then be allowed to grow a certain number of plants. Or, the patient can outsource the cultivation to a designated grower.

Health Canada also has a contract with a Saskatchewan company, Prairie Plant Systems Inc., to grow medical marijuana on a large scale. But patients complain that the company only produces one strain and they find it expensive.

Nash says patients have also long complained that many doctors refuse to give them permission to use medical marijuana.

"They don't want to fill out a 28-page form," Nash said.

Aglukkaq's changes are also expected to include better guidelines for doctors so that they know when to prescribe marijuana and in what quantities, sources said.

About 10,000 people have prescriptions for medical marijuana in Canada. And about 3,400 licences have been issued to grow the plants, two thirds of them in Ontario and British Columbia.