The automaker and the union representing its Canadian manufacturing workers have been divided over union demands that GM commit to building new vehicle models at its Oshawa, Ontario, plant.

“There’s a hell of a lot of work to do and not a lot of time with which to do it,” said Unifor National President Jerry Dias in an interview.

Asked whether the two sides were discussing a new product for GM’s Oshawa assembly, Dias said: “They understand that they have to do something, but we’re not really talking about anything specific, which is problematic.”

Dias said the union has not yet received a contract proposal from GM, but he remains confident the automaker will eventually offer a product. He said the union will not extend its strike deadline.

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GM declined to comment.

A four-year contract covering the workers of GM, Fiat Chrysler Automobiles (FCAU), and Ford Motor Co. (F) in the province of Ontario expires on Monday. The union chose GM as its strike target for contract talks, with GM’s deal setting the pattern for the other manufacturers.

Contract talks could save 2,500 jobs at GM’s Oshawa car assembly, or take the plant one step closer to closure. The automaker was already on the verge of shutting one of two assembly lines at its Oshawa plant, with several vehicles either produced in another country or expected to move in 2017.

There are no obvious products that would go into the Oshawa plant, and the automaker said previously it would only make future product decisions after a labor deal.

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Dias said no specific model has been discussed so far, but rejected the argument that GM has no product to allocate to the Oshawa plant.

“There has been a straight migration of products from north to south. There’s no reason why there can’t be a migration from south to north,” he said.

Canada has been struggling to get new investment from automakers in its once-thriving vehicle assembly industry, losing out to the Southern United States and lower-cost Mexico.

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Between 2001 and 2013, some 14,300 jobs were lost in vehicle manufacturing in Canada, according to the Automotive Policy Research Center in Hamilton, Ontario.

Still, the union has said it will not sign without a vehicle commitment, calling it pivotal for the future of Canada’s auto industry. Pensions and wages are also on the table.

Without a deal, the union’s 3,900 GM members would have a legal right to strike at midnight (0400 GMT) on Tuesday.