Vancouver's mayor says the city that opened North America's first supervised injection site after a surge in heroin-related deaths now wants the federal party leaders to consider a new proposal as they campaign for the October election.

Kennedy Stewart says he's aiming for a Health Canada exemption from federal drug laws to allow for the distribution of pharmaceutical-grade heroin to users who could die from fentanyl-laced drugs they buy on the street.

He says he wants the federal party leaders to understand the scale of the overdose crisis and that people could be saved with a non-toxic supply of drugs.

The Liberals haven't made that move in government and the leaders of the New Democrat and Green parties say they'd support a safer drug supply while the Conservatives say addiction should be the focus of dealing with the overdose crisis.

Donald MacPherson of the Canadian Drug Policy Coalition says addiction isn't killing people, it's the toxic drug supply.

And addiction specialist Doctor Keith Ahamad of St. Paul's Hospital says Canada needs policies to provide safer drugs to people struggling with chronic addiction and to stop criminalizing people who have drugs for personal use.