The Detroit 3 want to add temporary workers to help align their average hourly cost per worker with foreign automakers amid predictions of a declining sales market.
They will face a stiff battle during negotiations with the UAW, which wants the companies to give temps the wages, benefits and increased security that permanent positions provide.
The number of temps, how they can be used and for how long, are expected to be a contentious part of this year's contract negotiations, which formally start this week.
"That's really going to be a fight," said Kristin Dziczek, vice president of industry, labor and economics at the Center for Automotive Research in Ann Arbor, Mich.
Adding temps is one of the levers automakers have to help curb labor costs. Foreign-based automakers often employ 20 to 25 percent temporary workers, helping keep their average hourly labor costs well below those of the Detroit 3.