Seattle became the first city to give Uber and Lyft drivers the power to unionize yesterday, with the City Council passing a bill relating to those designated as contractors by ride-hailing app companies.

The App-Based Drivers Association played a role in the fight for unionization, and The New York Times reported the group’s success in Seattle could lead the way for other cities to implement similar policies.

The debate over whether Uber and Lyft drivers are contractors or employers has been ongoing among critics of the so-called “sharing economy” as well as in U.S. courtrooms.

After the Seattle vote passed, the Times reported, a Lyft spokeswoman said the ordinance would threaten drivers’ privacy and conflicts with federal law.

“We urge the mayor and full council to reconsider this legislation and listen to the voices of their constituents who choose to drive with Lyft because of the flexible economic opportunity it offers,” her statement said.

Seattle Mayor Ed Murray did not sign the bill, though that will not block it from becoming a law. Murray said while he supports workers’ rights to organize, he’s concerned about legal costs. According to the Seattle Times, “Uber and Lyft … argued that [the change] violates federal labor and antitrust laws, meaning the city likely will be sued.”