Union and GM representatives met Tuesday to discuss saving the automaker's Oshawa, Ontario assembly plant, but GM said that it still plans to close the plant in 2019.

"Unfortunately, all Unifor's proposals would involve substantial incremental costs and a further deterioration of GM's competitive position," General Motors wrote in a response it submitted to Unifor on Tuesday in Detroit. "Having completed an analysis of Unifor's proposals, GM has determined that it cannot pursue them because they would not combat the declining economic and market factors that must be addressed."

GM announced that no product would be going to the Oshawa plant after 2019 in December of last year as it announced that it would be doing the same to the Lordstown, Ohio and Detroit-Hamtramck, Michigan assembly plants and that it would be shutting down a US propulsion plant as well as a plant outside North America.

Canada's Unifor union was particularly galled by the announcement, since its leaders maintain that it had signed a four-year deal in 2016 that ensured the plant would have product until at least September 2020. GM claims it only had to give one year notice.

The plant employs 2,200 people and the union has been especially vocal about its objection to GM's plan to shutter the plant.

While GM argues that its decision was made to respond to industry forces, Unifor roundly rejects GM's logic.

"GM's plans were unveiled not in a declining market, or because the company faces a dire financial position-the U.S. market for vehicles remains at peak levels," the union wrote in a statement. "At every turn, over many decades, the members of Unifor Local 222 at GM Oshawa have delivered for the company. Oshawa has been building cars for over 100 years."

Following its meeting with the union, GM released a statement encouraging Unifor to work with it to help employees transition from their positions in Oshawa. A recent lawsuit from the UAW, though, alleges that GM failed to offer 700 Ohio employees from the similarly idled Lordstown Assembly plant at its nearby Fort Wayne plant, preferring instead to employ temporary workers.

Unifor, for its part, said that it plans to "escalate" its campaign to save the plant.

Unifor "deeply disappointed @GM refuses to change decision about #Oshawa while acknowledging they could change course." Union plans to escalate campaign to #SaveOshawaGM #sellherebuildhere #canlab pic.twitter.com/Qm2ZapCXfL

- Unifor Canada (@UniforTheUnion) January 8, 2019