The past three Vancouver mayors have released a joint letter sent to the federal government, asking it to keep the city's safe injection site open.

Mike Harcourt, Philip Owen and Senator Larry Campbell say keeping the Insite clinic open makes sense, both scientifically and financially.

The future of the Vancouver safe injection site remains in doubt.
(CBC)

Current mayor Sam Sullivan and former Vancouver mayor, Premier Gordon Campbell, have previously spoken out in support of the clinic.

Insite has a three-year Health Canada exemption to Section 56 of the Controlled Drugs and Substances Act, which allows it to operate legally until Sept. 12

Its permit runs out next month, and it's not clear whether the Harper government plans to extend the exemption.

Insite saves lives, says Larry Campbell

At a news conference in Vancouver on Monday, the former mayors cited research showing the effectiveness of the clinic in the city's Downtown Eastside since it opened in September 2003.

According to Vancouver Coastal Health Authority statistics, 453 people overdosed at Insite over the two-year period ending March 31, 2006. None died, however, as the staff at Insite is trained to deal with overdoses.
   
Senator Campbell says some of those people would have died if they had overdosed alone.

He also says the site saved taxpayers $8 million last year, by preventing the spread of diseases such as AIDS.

The health authority reports an average of 607 visits a day to the clinic during the same two-year period.

The Insite staff also made 4,083 referrals during the two years, 40 per cent of them to addiction counselling.

There are nearly 5,000 injection drug users in the Downtown Eastside, which has some of the highest HIV and hepatitis C infection rates in the world.