The Canadian Unifor autoworkers union said its members at Nemak of Canada Corporation in Windsor gathered recently for a special meeting to respond to the company's plans to close the plant in 2020.
In July 2019 lightweighting specialist Nemak said in a statement it would cease manufacturing operations in Windsor by mid-2020.
"The plant represents approximately 1% of Nemak's consolidated revenues," the statement said.
"This decision is a result of the early phase out of an export programme with a customer in China which is expected to bring capacity utilisation at the plant to less than 10% by 2020.
"Given our outlook on capacity utilisation and volumes in Windsor, we have made the decision to end production at this facility," CEO Armando Tamez said in the statement.
"We are deeply grateful to the many people who have contributed to our business in Windsor over the years and we will make every effort to support them during this period."
The plant has 270 employees and produces engine blocks.
"Nemak cannot shut down its Windsor plant after taking millions in government handouts and posting revenues of over C$4bn world-wide," responded Jerry Dias, Unifor national president.
"This is a betrayal of both the workers who generated their profits and the public they siphoned millions from."
Unifor claims that, since 2015, Nemak received "generous handouts" from several government sources including a $1.5m grant from the government of Ontario, $1.3m in tax breaks from the city of Windsor, and $3m in federal government funds.
"Nemak is breaking an agreement with the workers to keep this plant open until at least 2022," said John D'Agnolo, Unifor Local 200 president.
"Canadians funded this company, Nemak workers built its production process, and Unifor will fight this closure."
The closure announcement came after Nemak agreed a four year extension to the Unifor Local 200 collective agreement through to 2022 that included a four year wage freeze.
The employer and Unifor agreed the Windsor plant would be the sole source for General Motors I6 engine blocks and engine blocks and bedplates for the 'Thelma and Louise' Corvette.
Unifor claims that, in direct contravention of this agreement, the company announced it would move production of the I6 diesel engine block, the Corvette engine block and bedplate to its facilities in Monterey, Mexico as well as begin building Fiat Chrysler Automobiles (FAC) engine blocks there.
Both product lines will use the production process and technology developed at the Nemak Windsor production facility.
Unifor has requested a meeting with the Nemak CEO but claimed no response had been received.