In a suit brought by two women who allege they were sexually assaulted by Uber Technologies Inc. drivers, the San Francisco-based company's lawyers are raising a familiar defense. In court papers filed late Thursday, Uber claims that it shouldn't be held liable for the drivers' actions because "they were not employees of Uber," echoing previous defenses the company has put forward in other suits.

The familiar refrain comes as part of Uber's early attempt to get U.S. District Judge Susan Illston of the Northern District of California to toss a suit filed in October on behalf of two Jane Doe plaintiffs. Plaintiffs lawyers at Wigdor LLP and Anderson & Poole maintain that the company should be held liable for the conduct of Uber drivers in Boston and Charleston, South Carolina.

In a motion to dismiss, Uber's lawyers at Clarence Dyer & Cohen acknowledged that U.S. District Judge Edward Chen of the Northern District of California has ruled previously in a separate employment suit that a jury should resolve the question of whether Uber drivers are employees or contractors under California law. But, the company's lawyers wrote, nothing in the earlier case precludes Illston from finding that plaintiffs in the sexual assault matter failed to show an employer-employee relationship.