California is preparing to sue the U.S. federal government to defend its long-standing right to set stricter vehicle emissions standards, Attorney General Rob Bonta said, after Senate Republicans voted to repeal the state’s federal waiver.
The Senate voted 51–44 on Thursday to overturn the waiver, which has historically allowed California to enforce more rigorous air pollution limits on vehicles. The decision also affects a separate waiver for medium- and heavy-duty vehicle standards. California has received such waivers over 100 times in the past five decades under federal clean air laws.
“The weaponization of the Congressional Review Act to attack California’s waivers is just another part of the continuous, partisan campaign against California’s efforts to protect the public and the planet from harmful pollution,” Bonta said in a statement to TechCrunch. “This reckless misuse of the Congressional Review Act is unlawful, and California will not stand idly by.”
Sixteen other states and the District of Columbia follow California’s emissions rules, many of which have adopted their own timelines to phase out fossil fuel vehicles. California’s zero-emission vehicle (ZEV) mandate, set to begin in 2026, requires a gradual increase in ZEV sales until 2035, when all new cars and passenger trucks sold must be emissions-free.
At present, only battery electric and hydrogen fuel cell vehicles qualify under the ZEV mandate. In 2023, 25.3% of new light-duty vehicles sold in California were zero-emission, but growth in ZEV sales plateaued in 2024. Automakers have warned that meeting the 35% ZEV target in 2026 could be “impossible” due to infrastructure and production challenges.
The Senate vote ran counter to guidance from the Senate parliamentarian and the Government Accountability Office, both of which had concluded that the Congressional Review Act (CRA) could not be used to rescind California’s emissions waiver. The CRA allows a regulation to be overturned by a simple majority vote without the possibility of a filibuster.
In March, Bonta had already warned of potential legal action. “We don’t think it’s an appropriate use of the Congressional Review Act, and we’re prepared to defend ourselves if it’s wrongfully weaponized,” he told Politico at the time.