Ontario has introduced new legislation billed as one of the toughest anti-tobacco measures in North America.

The new Smoke Free Ontario act would prohibit smoking from May 2006 in all workplaces and public places including bars, restaurants and casinos and restrict the display of tobacco products in stores.

The legislation, if passed, would eliminate what the government calls the "patchwork quilt" of municipal bylaws governing smoking in Canada's most populous province of 11 million people. It is expected to do away with designated smoking rooms and smoking on the covered outdoor patios many businesses have been setting up to try to get around local bylaws.

"The bill ... would protect all Ontarians from the deadly effects of cigarette smoke, whether they are in their office, at a restaurant, in the laundry room of their apartment building, on the floor of a factory, in an underground parking garage or at a shopping mall," said Health Minister George Smitherman.