Uber received a blow in court Tuesday when a federal judge in California approved class action status in a case where drivers claim they were improperly treated as independent contractors instead of employees.

Judge Edward Chen of the U.S. District Court in California ruled the class could include UberBlack, UberX and UberSUV drirvers who drove in California at any time since Aug. 16, 2009, unless they had signed a contract with Uber requiring arbitration.

The number of drivers could be more than 160,000, according to court filings.

Uber had argued its relationship with drivers in California was not uniform enough to allow for all drivers to be represented in a class action, but Chen rejected that argument.

“As other courts weighing certification of employment misclassification claims have recognized, however, there is inherent tension between this argument and Uber’s position on the merits,” Chen wrote, “on one hand, Uber argues that it has properly classified every single driver as an independent contractor; on the other, Uber argues that individual issues with respect to each driver’s ‘unique’ relationship with Uber so predominate that this court (unlike, apparently, Uber itself) cannot make a classwide determination of its drivers’ proper job classification.”

Both sides in the case made their arguments last month.