LOS ANGELES (AP) — A judge has struck down California’s ballot measure that exempted Uber and other companies from a state law requiring their drivers to be classified as employees eligible for benefits and job protections.

Alameda County Superior Court Judge Frank Roesch ruled Friday that Proposition 22, which allowed the drivers to be classified as independent contractors, is unconstitutional and can’t be enforced.

Proposition 22 passed in November after Uber, Lyft and other app-based services spent $200 million in its favor, making it the most expensive ballot measure in state history.

The ruling sets up a fight that could likely end up in California’s Supreme Court.