Supporters of North America's first and only legal injection drug site argued before Canada's Supreme Court on Thursday that the facility saves lives and should remain open.

Defenders of the taxpayer-funded site, located in a seedy, drug-infested district of Vancouver, British Columbia, said it is providing a form of health care which is a provincial matter under Canada's constitution. The Conservative government counters federal law banning heroin trumps provincial rights.

The nine justices of the Supreme Court reserved their decision.

The site operated under a special exemption from the former Liberal government that has since expired, but lower court rulings have allowed it to remain open.

Insite, as the Vancouver center is called, is the only facility of its kind in Canada. More could open if the top court agrees Insite is legal.

"Insite is a life-raft for the people in the downtown eastside," said Joseph Arvay, a lawyer for PHS Community Services Society, which operates the facility with the Vancouver Coastal Health Authority.

"A life-raft in a sea of misery."

Insite receives more than 800 visitors a day on average and has supervised more than a million injections since it opened in 2003, and none has caused a death, according to Insite supervisor Russ Maynard.

Addicts are given clean needles and sterilized water in which to mix their drug. They bring their own drugs and inject at 12 stainless steel alcoves with mirrors on the walls so nurses on a raised platform can see them.

The storefront facility sits in Downtown Eastside, 15 blocks of cheap rooming houses where addiction and street prostitution are rampant and an estimated 5,000 of the area's 12,000 population are believed to be addicts.

Julio Montaner, president of the International AIDS Society, an association of professionals in the AIDS field, has said the area's AIDS rate is the worst in the developed world, and can be designated an epidemic. Montaner, a Canadian, accuses his government of ignoring scientific research and sabotaging a health initiative for society's weakest citizens.

When Insite opened, the Bush administration's drug czar, John Walters, called it "state-sponsored suicide," and after a Conservative government was elected in Canada in 2006, it moved to close the site.

But Federal lawyer Robert Frater told the court Thursday that no decision has been reached on whether to extend its exemption from federal drug laws.

"The decision to grant or not to grant the exemption has not been made," he said.

Arvay said there's no question the Conservative government will terminate the exemption and called it "completely disingenuous" for the government to say that they might grant an exemption.

In 2008 the then federal health minister, Tony Clement, told the Canadian Medical Association that the Conservative government opposed Insite because "injections are not medicine and they do not heal."