General Motors and Chrysler face a deadline of 6 p.m. ET Tuesday to tell the U.S. government how they will repay federal loans and become viable.

The rush to submit the plans came on the same day GM was to get the second installment in U.S. government loans — $4 billion US — on top of the $9.4 billion it got earlier, while Chrysler will get $3 billion on top of its earlier $4 billion, said a report from Associated Press.

U.S. President Barack Obama on Sunday created a high-level task force to oversee the restructuring of the automakers, which are facing a 26-year low in auto sales amid the world economic recession.

GM officials said they are making progress in concession talks with the United Auto Workers, but union officials have said they don't expect a final deal by the end of the day.

According to a report, the company's plan will discuss cost savings from labour concessions and additional plant closures, but the locations of those plants will not be revealed, another person briefed on the plan said Monday.

GM executives have said the company only has to show substantial progress by Tuesday, with the whole plan finalized by March 31.

Chrysler was due to hold a teleconference call at 5 p.m. ET, while GM had a press conference slated for 6:30 p.m. ET.

Investors reacted negatively, sending shares of GM down more than 13 per cent in early afternoon trading. The stock was down 34 cents at $2.16 US on the New York Stock Exchange.

Alisa Priddle, who cover the auto sector for the Detroit News, said GM, the United Auto Workers union and the company's bondholders are engaged in brinkmanship because part of the bailout conditions are that the union and the bondholder take some equity in exchange for money that the automaker owes to them.

"Neither of them want to do that because, as you might imagine, the equity in something like GM right now is not a hugely valuable commodity," she said.

Priddle added that the U.S. government has said while the plans the automakers submit are for viability, they must be also be prepared to discuss what would happen if they go into bankruptcy.

Canadian unions watching

GM's board met Monday by teleconference to go over the plan, but details could not be obtained. The company has already said Saab and Hummer brands are up for sale and Saturn is under review, leaving GM to focus on Chevrolet, Cadillac, GMC and Buick, with Pontiac reduced to one or two models.

GM has about $28 billion in unsecured debt. Chrysler has about $9 billion in mostly secured debt.

Ken Lewenza, the president of the Canadian Auto Workers union, said Canada's auto industry is at the mercy of the American parent companies.

If the Big Three autoworkers in the U.S. — GM, Chrysler and Ford — agree to major concessions this week, the Canadian autoworkers may have little choice but to follow in line.

"You can't have an unhealthy Detroit and a healthy Canada. It doesn't work like that. We're integrated with each other," he said.

Tony Faria, an auto analyst at the University of Windsor, agreed, saying any American concessions will likely be copied in Canada.

"Whatever givebacks the UAW agree to, the companies in Canada will be looking for about the same things," he said.

With files from the Associated Press