Lawyers at Gibson, Dunn & Crutcher for Uber and Postmates are due in court on Friday to ask a federal judge to halt enforcement of a California employment law that, according to them, would raise the ride-sharing firm's costs and harm its drivers and customers.

The law, Assembly Bill 5, which went into effect on Jan. 1, mandates that certain individuals considered independent contractors in California will now be employees. The idea was to remedy what many considered the widespread exploitation of California's workers, but Uber Technologies Inc., Postmates Inc. and two of their drivers sued on Dec. 30, invoking the Constitution to stop enforcement of the law.

"The harm from enforcement of the statute in this way would be immeasurable and irreparable, and would reach not only the individual and company plaintiffs, but the entire economy," Theane Evangelis, a partner at Gibson Dunn's Los Angeles office, wrote in a Jan. 8 motion for preliminary injunction filed their lawsuit, in federal court in Los Angeles. "It would turn the technological clock backwards by a decade and abandon the immense benefits the on-demand economy has made possible."

In addition to higher costs for Uber and Postmates, AB5 would lead to increased fares for passengers and less income for their drivers, according to the motion.

The U.S. Chamber of Commerce and two technology groups, Engine Advocacy and TechNet, asked this week to file an amicus brief in support of the injunction motion, as have four "on-demand contractors," who include an aspiring actor and freelance screenwriter, claiming that the law would impose the "extreme hardship" of giving up their flexible jobs.

California Attorney General Xavier Becerra has opposed the injunction motion and the proposed amicus briefs.

In a statement, the California Attorney General's office said, "Our office has and will continue to defend laws that are designed to protect workers and ensure fair labor and business practices."

U.S. District Judge Dolly Gee, overseeing the case in the Central District of California, will hear arguments on Friday.

The case is one of at least three lawsuits filed to halt enforcement of AB5, which the California Legislature passed on Sept. 11 of last year.

California legislators claimed that AB5 codified into law a California Supreme Court decision in 2018 called Dynamex Operations W. Inc. v. Superior Court, which set up a test to determine whether employees should be independent contractors or employees. They exempted several industries but not the gig economy.

The lawsuit by Uber and Postmates alleges that the "Frankenstein-like statute" violates the equal protection and due process clauses of the Fourteenth Amendment, the Ninth Amendment, the Contracts Clause and other constitutional provisions. They argued that California legislators, while currying favors for dozens of occupations with lobbyists, specifically targeted "network companies," and that city and state officials have vowed to enforce the law against gig companies.

The chamber, in its proposed amicus brief, said California's wage laws do not fit into the structure of gig companies.

"These restrictions limit when, where, and how California employees work, making it impossible for them to have true flexibility," wrote Sacramento attorney Bruce Sarchet, a shareholder at Littler Mendelson. "By contrast, independent contractors can work as many or as few hours in a day, with as many or as few breaks, as they choose."

In a reply supporting their injunction motion, Uber and Postmates referenced a Jan. 16 order granting a preliminary injunction motion in a separate case brought by the California Trucking Association. In that case, U.S. District Judge Roger Benitez, in San Diego, found that the plaintiff had raised a plausible argument that the Federal Aviation Administration Authorization Act of 1994 preempted AB5 as it pertained to motor carriers. He cited a Jan. 8 decision by Los Angeles Superior Court Judge William Highberger finding the federal law preempted AB5.

Opposing the injunction motion in the case by Uber and Postmates, California Deputy Attorney General Jose Zelidon-Zepeda on Jan. 17 denied that the law targeted certain industries and argued that Uber and Postmates waited until "the last possible moment" before suing over AB5.

He also cited a Jan. 3 decision by U.S. District Judge Philip Gutierrez, of the Central District of California, rejecting a temporary restraining order in a Dec. 17 lawsuit brought by the Attorneys for the American Society of Journalists and Authors Inc. and the National Press Photographers Association, whose members work as independent contractors. Gutierrez, in that order, cited the fact that the plaintiffs choose to file days before the law, enacted on Sept. 18, became effective.

"Plaintiffs' delay belies their claim that there is an emergency," he wrote.

Next month, the plaintiffs in that case, represented by the Pacific Legal Foundation, plan to argue for their own preliminary injunction motion, while the state's lawyers said they prepared a motion to dismiss.