The US Supreme Court on Thursday declined to hear a challenge by Alaska Airlines Inc. seeking an exemption from a California law mandating meal and rest breaks during flights, letting stand a previous decision that sided with flight attendants in a battle over federal and state labor laws.

The Ninth Circuit Court of Appeals ruled in its July 2021 decision Virgin America, Inc. v. Julia Bernstein, that the airline, which later merged with Alaska Airlines, had to comply with California state law in addition to federal regulations for flights within the state. Bernstein, a flight attendant, filed a class action suit on behalf of California-based workers, claiming violations of state labor laws. This included a law requiring that workers have a 30-minute off-duty meal and rest break after working for five hours.

After the appellate court’s decision, Alaska Airlines, Inc. petitioned the Supreme Court, seeking to challenge the Ninth Circuit’s holding that the federal Airline Deregulation Act of 1978 did not preempt state law requiring rest and meal breaks. The airline group argued that the state law had a “significant impact on airline prices, routes, and services” as more attendants and staff would have to be hired to accommodate the state’s break requirements.

The rejection of the airlines’ petition may have lasting consequences for the airline industry as well as state and federal labor regulations. The court’s decision also follows the guidance of the Biden Administration, as the Department of Justice filed an amicus curiae brief on behalf of the flight attendants and instructed the court not to review the case or send it back to the appellate court.