About 700 workers at a General Motors plant in Oshawa, Ont., are facing temporary layoffs, the Canadian Auto Workers union said Friday.

The layoff of the third shift at the car plant will start in the first week of February, the CAW said. It wasn't immediately clear how long the layoff will last.

About 5,000 people work in the Oshawa plant, which builds the Chevrolet Impala. The line is already set to shut down next Monday until early January.

Workers learned about the February shift cut Thursday evening, CAW spokeswoman Shannon Devine said.

"The plant is down as of next week until Jan. 12 and everybody is back for a few weeks, and as of the first week of February the third shift is down," she said.

"It's is indefinite but it is supposed to be temporary."

Layoffs were expected

GM Canada, which was not immediately available for comment Friday, warned in November that it would temporarily lay off 500 people in the Oshawa plant at the beginning of 2009 until the auto market rebounds.

Similar temporary shutdowns are expected to take place throughout the United States.

In the midst of an economic crisis, GM sales have plummeted in the United States, which receives 95 per cent of what the company makes in Canada.

Tens of thousands of auto sector workers have lost their jobs across North America, prompting the industry to appeal for help from governments in both Canada and the United States.

GM's neighbouring truck plant in Oshawa is slated to close next year, leaving 2,600 workers jobless.

With files from Reuters, the Canadian Press