A judge signaled that she’ll probably deny a request by Uber Technologies Inc. and Postmates Inc. to block California from enforcing its gig-worker protection law to their drivers.

Uber and Postmates sought to temporarily shield themselves from Assembly Bill 5, which is aimed at converting gig-economy workers from independent contractors to employees with benefits, while they challenge the landmark measure as unfair to on-demand businesses. Uber and Postmates didn’t ask the judge to block enforcement of the law against other companies.

U.S. District Judge Dolly M. Gee said during a hearing Friday in Los Angeles that it was “a steep hill to climb” for the two companies to argue that the statute was irrationally targeting the app-based companies on the grounds that many workers in other industries were exempt from it.

“I can’t second guess the legislature unless you show me an example of an exemption that absolutely doesn’t make sense,” Gee said.

California Attorney General Xavier Becerra argued the constitutional challenge to the law by Uber and Postmates will fail because the state legislature has a prerogative to stop the gig economy’s exploitation of workers.

An Uber spokesman and a lawyer for California declined to comment after the hearing.

As multiple court battles play out, gig companies are working on other fronts to rein in the law. Uber, Lyft, Postmates, Instacart and DoorDash have pledged $110 million for a ballot measure to change A.B. 5.

Signed by California Governor Gavin Newsom in September, A.B. 5 says workers can generally only be considered contractors if they perform duties outside the usual course of a company’s business. Uber filed its suit Dec. 30, two days before A.B. 5 took effect.

The case is Olson v. State of California, 2:19-cv-10956, U.S. District Court, Central District of California (Los Angeles).