Attorneys at the management-side firm Ogletree, Deakins, Nash, Smoak & Stewart will lead a federal legal challenge to California’s new worker classification law on behalf of the state’s trucking industry.

In an amended complaint filed Tuesday, the California Trucking Association and two independent truckers asked the U.S. District Court of the Southern District of California to block enforcement of Assembly Bill 5. The law, set to take effect Jan. 1, will make it more difficult for companies to label workers as employees.