TORONTO -- Canada's largest private sector union has called for a boycott of General Motors vehicles made in Mexico as part of its campaign to save the GM Oshawa assembly plant.

Unifor president Jerry Dias said at a press conference Friday that the move would put pressure on the company to stop shifting production to the lower-wage country.

"This is not us attacking Mexican workers, but what we're disgusted by is how General Motors is using these workers as pawns for corporate profits. The fact that General Motors pays their employees in Mexico two dollars an hour is an absolute disgrace," said Dias.

"We're asking Canadians to stand up to corporate greed. We're asking you to stand up to greedy motors."

The escalation of the campaign comes almost two months after GM announced it would end production at the Oshawa, Ont. plant by the end of the year at a loss of about 2,600 direct union jobs as part of a larger restructuring

GM has remained clear in its intent to close the plant despite a sustained campaign from Unifor for the company to reverse the decision.

The company, which has promised retraining and help with job-pairing for those affected, said the boycott could hit parts suppliers in Ontario.

"The threat of collateral damage for Ontario based auto suppliers, auto dealers and workers is concerning," said GM Canada vice president David Paterson in a statement.

Dias said there were few auto parts that go from Ontario to Mexico and downplayed the threat to jobs in the province. He said there was, however, a clear threat to Canadian jobs heading south

"Our members understand where their jobs are going, they're going to Mexico. So at some time we have to have this fight and it might as well be now," said Dias.

Consumers can identify the vehicles produced in Mexico by vehicle identification numbers that start with a three, said the union.

It said some GM vehicles, including the Chevrolet Blazer, Trax and GMC Terrain are made only in Mexico, while others such as the Chevy Equinox, Silverado and Cruize are made throughout North America.

Dias said Unifor would be meeting with the United Automobile Workers in the U.S. in the coming weeks about potentially expanding the boycott to both countries, where combined GM sells about 600,000 vehicles produced in Mexico.

The effect on short-term sales will likely be minimal, said Jay Handelman, an associate professor of marketing at Queen's University's Smith School of Business, since the purchase of a vehicle is too big and takes too long to make to be swayed by a last minute plea.

There could be a longer-term hit for GM though, he said.

"I think this does have a longer-term effect on the GM brand more generally. It wouldn't surprise me if in the future there are questions about do you trust this brand, are they committed to Canada, and so on. I think that's where the brand will suffer."

He said Unifor has been effective in making the campaign wider than just Oshawa and into a question of loyalty to Canada.

"I think there's no downside to Unifor on this. Even if the boycott itself is not effective, I think Unifor's presented itself very well."

The boycott, however, won't help fix the problems that led GM to announce the Oshawa closure along with four U.S. plants, said Will Mitchell, professor of strategic management at the University of Toronto's Rotman School of Management.

"I think it's counterproductive as hell," said Mitchell.

"That's going to damage the company, which in turn will damage the jobs. It's going to take the financial performance and make it worse. And as a result when they do the next shutdown it's going to be even bigger."

Dias has emphasized that GM is making the cuts while reporting billions of dollars in profits, but Mitchell said that the company has seen sales drop by a quarter in the past decade while other automakers have maintained or boosted sales and that its profits continue to lag.

"If you're CEO of a company in that situation and you don't shut down plants, you should be fired," he said.

"This is unquestionably hard on the people who are affected by it, but if you're not thoughtful about it and disciplined about it now, it's going to be even harder on everybody else in the company."