The Canadian Auto Workers union is calling for General Motors to replace “1-for-1” jobs the auto maker’s Oshawa, Ontario, assembly plant stands to lose as a result of a shift in sourcing for the Chevrolet Camaro.

“Or reverse the decision,” says CAW President Ken Lewenza, who characterizes GM’s planned move as “abrupt, disgraceful” and a “betrayal” after Canada gave the auto maker $10 billion to keep it alive during its 2009 bankruptcy.

GM says it will relocate Camaro production to its Lansing, MI, Grand River assembly plant when the current-generation model’s lifecycle ends. The auto maker cites a plan to consolidate production of its rear-wheel-drive cars in a single facility.

GM currently builds the Cadillac ATS and CTS lineup of sport sedans and coupes at the LGR plant. The Camaro and CTS are expected to move to the newly developed Alpha RWD platform underpinning the recently launched ATS.

Lewenza estimates the move will cost 1,000 jobs at Oshawa. While he stops short of threatening a walkout, says the CAW has appealed to the highest ranks of the Canadian government to exert political pressure on GM to allocate a new product for the plant to save every job.

“The Canadian government should step in and say, ‘Enough is enough,’” Lewenza says. “(GM) has a responsibility to replace the lost volume.”

GM last year produced 105,387 Camaros at Oshawa 1, also known as the “flexible line.” The auto maker has built 96,691 of the sports coupes so far this year, according to WardsAuto data, which represents 66.3% of the plant’s volume.

Oshawa 1 also builds the Buick Regal and the newly launched Cadillac XTS. It will share production of the next-generation Chevrolet Impala, rolling out next year, with GM’s Detroit-Hamtramck assembly plant. The addition of the new Impala will move the flex line to a 3-shift operation.

GM plans to close Oshawa 2, known as the “consolidated line,” by June 2014. It builds the current-generation Impala and Buick LaCrosse and finishes Chevy Equinox builds started at GM’s nearby Ingersoll, ON, assembly plant.

“Either way, we are going to lose jobs,” says CAW Local 22 President Chris Buckley, who says the Oshawa complex altogether has lost about 19,000 positions since 1983.

The drain includes closure of a massive truck-building site in 2009, when GM began downsizing ahead of its bankruptcy. The complex currently employs about 4,000 people.

Lewenza suggests a connection between GM’s decision to relocate Camaro to Michigan and last week’s passage of right-to-work legislation in the state.

GM executives complained during CAW contract negotiations this year about Canada being the world’s most expensive place to produce vehicles.

GM declines to comment on the CAW’s remarks, referringWardsAuto to a published statement.

“GM will continue to meet the production targets agreed to with the Canadian and Ontario governments during the 2009 restructuring,” the auto maker says, noting the addition of the XTS and Impala to the flex line took an investment of $185 million.

jamend@wardsauto.com