By Ian Gunn BBC News, Vancouver

The Canadian Government is widely expected to introduce legislation to decriminalise possession of marijuana early in this year.

Justice Minister Martin Cauchon says he wants to make the penalty for being caught with small amounts of marijuana roughly equivalent to a traffic fine.

That worries Canadian police and customs officials in the US, where drugs laws are much stricter.

Canada's plans are getting a chilly reception in the US

The focus of their worry is the province of British Columbia which already produces vast quantities of cannabis - mainly to be smuggled into the US.

The region around Vancouver grows some of the world's most potent marijuana.

In warehouses, basements and back gardens across Canada's south west coast, the crop known as 'BC bud' is a massive underground industry.

Reliable figures are hard to come by, but some estimates say clandestine cannabis rivals the timber industry here in economic scale.

'Bad idea'

Most of the illegal crop is controlled by organised crime and is destined for the US.

So the news that Canada plans to loosen its marijuana laws is getting a chilly reception in America.

Canadian police, too, say it is a bad idea. Shutting down growing operations is an almost daily part of police work here.

And police say cannabis cultivation will become more common and be harder to prosecute under laxer laws.

But opinion polls suggest Canadians themselves support the government's moves.

And some experts say it is unlikely the changes will increase drug use or make life harder for either Canadian police or American border guards.