Lawyers for General Motors on Monday urged a federal bankruptcy judge in Manhattan to throw out a settlement that would require the company to pay $1 billion to car owners suing over faulty ignition switches.

The carmaker made its argument on the first day of a scheduled three-day bench trial before Judge Martin Glenn of the U.S. Bankruptcy Court in New York. The trial will determine the validity of a deal the car owners said they reached in August with a trust that holds many GM liabilities from before its 2009 bankruptcy.

The claims stem from GM's 2014 recall of 2.6 million vehicles with defective ignition switches, including one linked to 124 deaths.