Contract talks between General Motors (GM - Get Report) and the United Autoworkers continue as the two sides scramble to reach a deal before the current labor contract expires at the stroke of midnight.

The two sides are negotiating over everything from pay and temporary workers to health care costs in the hope of avoiding the auto industry's first major walkout in more than 10 years.

"We continue to work hard on solutions to some very difficult challenges. We are prepared to negotiate around the clock because there are thousands of GM families and their communities - and many thousands more at our dealerships and suppliers - counting on us for their livelihood. Our goal remains on building a strong future for our employees and our business," said GM in a statement provided to TheStreet on Saturday evening.

However, in a major complicating development that could undermine the union's ability to cut a deal, federal prosecutors on Thursday charged a top UAW regional official, Vance Pearson, with embezzling hundreds of thousands of dollars in union funds, money that fueled a spending spree in Palm Beach on everything from restaurants and a cigar shop to a golf resort.

It is part of an ongoing and potentially widening probe that has seen the FBI raid the homes of UAW President Gary Jones and former UAW President Dennis Williams, neither of whom has been charged with any crime.

The UAW is focusing its energies on GM, where it has 49,200 members, having just extended contracts with Ford and Fiat Chrysler.

The last major auto workers strike was in 2007 and lasted just 17 hours.

Still, a strike is far from certain, with the possibility that UAW and GM could ink a tentative deal or extend the deadline and continuing negotiating if a deal is close.

GM's stock price edged down in after-hours trading Friday, falling 0.23% to $38.86.

"The negotiations raise many contentious issues that challenge the bargaining teams on both sides of the table to reach an agreement," wrote Kristin Dziczek, vice president of industry, labor and economics at the Center for Automotive Research, in a report on the talks.

GM seized upon the federal corruption charges to levy a verbal volley at the UAW as contract talks dragged on, with the auto giant, in a statement, contending it is "outraged and deeply concerned by the conduct of union officials as uncovered by the government's investigation and the expanding charges."

Even so, as the contract deadline nears, negotiating teams from both sides remain at the table, trying to hash out major issues on a number of fronts, with health care costs, pay, the use of temporary workers, and GM's push to lower its overall labor costs to keep up with competitors, all major flashpoints.

With GM making billions again, the UAW would like to see pay raises for workers instead of the current profit-sharing system, which would lock in pay gains as opposed to leaving them at the mercy of the market.

The union is also pushing back against what it contends is the overuse of temporary workers, which it contends GM has turned into "perma-temps," and wants to ramp up the time over which new workers climb to the top of the pay scale, which currently takes eight years.
But GM contends its labor and health care costs have put it at a disadvantage compared to its competitors in the auto industry.

GM shelled out more than $900 million last year to pay for employee health care, with workers at the car company picking up only 3%-4% of the tab compared to the 20%-30% average for the auto industry as whole.

It costs GM $2,700 in labor to build each car, $100 more than Ford and $180 more than Fiat Chrysler, according to Dziczek.

GM also pays considerably higher wages to its autoworkers than foreign car manufacturers with U.S. plants, with a $13 an hour difference.

"The automakers are seeking to contain labor cost growth while the UAW is looking to make economic gains and secure its members' jobs and future income," Dziczek wrote.

Meanwhile, both sides are taking steps to gird for a potential showdown on the picket line.

GM has stockpiled extra cars and vehicles at its dealerships, with a 77-day supply, the Detroit Free Press reports, citing Cox Automotive stats.

That's compared to the industry average of 61 days.

GM has paid special attention to its trucks and SUVs, its biggest money makers, with an 80-day supply.

UAW officials, in turn, have been briefing members of what to do if a strike is called, with one Detroit local already posting a picket line signup sheet.

The union's national's council is scheduled to meet Sunday morning, Terry Dittes, head of the UAW's GM division, told members in a letter this week.

"We will not know the agenda until hours before the meeting," Dittes wrote. "It may be to vote on a Tentative Agreement, or the Company's current offer on the table, or other necessary actions."

This story has been updated.