Auto industry players are in the dark about details of the government's proposal but have resisted any talk of mandatory emissions standards. Car makers say they are already cutting down smog-related emissions voluntarily and may have to cut thousands of jobs if tougher rules are imposed.

Government officials, who confirmed the meeting, denied media reports that Ambrose was eyeing California's stricter automotive emissions standards as a model for Canada.

"We need to let them have a discussion and then go from there and see the pros and cons of what's presented and what they come forward with," the official said. "No decision has been made on how to proceed on emissions."

The Conservatives are under criticism for dismissing the Kyoto agreement on curbing greenhouse gases as unworkable and have set out to show Canadians they are serious about the environment by drafting up their own plan, focusing on clean air.

Clean air legislation would be introduced "shortly," the official said.

But Mark Nantais, president of the Canadian Vehicle Manufacturers' Association, warned that consumers could end up bearing the cost of mandatory auto-emissions standards.

"If you regulate on a unique basis to Canada, that takes us away from our North American approach to vehicle standards, which means the cost to Canadians is going to go up significantly," he said.

Nantais said more than 70 new fuel-saving technologies have been implemented by Canadian automakers since a voluntary agreement went into place last year to cut 5.3 megatonnes in annual greenhouse-gas emissions by 2010.

Buzz Hargrove, president of the Canadian Auto Workers Union, agreed with Nantais that the voluntary accord is the best way forward.

Hargrove painted a gloomy picture of plant shutdowns and massive layoffs in the industry if the government forced through new rules. Several of the country's 540 automotive-parts producers are already bankrupt and several others are on the verge, he said.

"There's enough pain and enough being done in the industry right now," he said. "We don't need any further hits when the industry is down."

"(The Conservative government is) under enormous pressure, as they've withdrawn from the commitments they've made under Kyoto, to come up with something that has the appearance of them being tougher than the last guys," Hargrove said, referring to the previous Liberal government.

The automotive industry accounts for about a quarter of all Canadian manufacturing. Daimler Chrysler, Ford Motor Co., and General Motors all manufacture vehicles in Canada, as do Honda Motor Co. and Toyota Motor Corp.

Nantais said that "all the majors that produce in Canada," would be at Tuesday's meeting.

Finance Minister Jim Flaherty, Industry Minister Maxime Bernier, Transport Minister Lawrence Cannon will also be attending the meeting.