OTTAWA - NDP Leader Jack Layton says the cost of prescription drugs is helping widen what he calls Canada's "prosperity gap."

Layton says household spending on prescription drugs jumped more than 70 per cent from 1992 to 2002 - far exceeding the 11 per cent increase in spending on food, clothing and shelter over the same period. And Layton says it will only get worse: the Conservative government has extended exclusive selling rights for brand-name drugs to eight years from five.

He says the government must eliminate drug-patent laws that discourage cheaper generic drugs from getting to market quickly.

And he says it should introduce catastrophic drug coverage as a first step toward a national pharmacare plan.

Layton says the annual increase in Australia's annual drug spending is less than half of what it is among Canada's provincial drug plans because Australia has a national bulk-buying program.

Layton is also calling for new rules to ensure no federal money can be used to subsidize a private health-care insurance system covering medically necessary services.