SACRAMENTO – California Gov. Gavin Newsom hit back Tuesday against reported plans by the Trump administration to formally revoke a Clean Air Act waiver that allows the Golden State to set emissions rules that are stricter than the federal government.

The U.S. Environmental Protection Agency is expected to announce a rollback of the plan Wednesday afternoon at a private event at its headquarters, a move seen as a direct attack against the Democratic stronghold in the West.

The decision comes almost two weeks after the Justice Department launched an antitrust probe into a deal struck by California and four automakers to boost fuel efficiency.

“The president could learn from California. Instead, reports today suggest that his administration will act on a political vendetta by announcing they intend to end aspects of our clean car waiver,” Newsom said in a statement. “It’s a move that could have devastating consequences for our kids’ health and the air we breathe, if California were to roll over. But we will not – we will fight this latest attempt and defend our clean car standards. California, global markets, and Mother Nature will prevail.”

The political dispute between California and the Trump administration began almost the day Trump was inaugurated, as the president promised to roll back the Obama-era rule requiring auto manufacturers to increase fuel efficiency by 5% in all models by 2025.

California then announced its intention to establish its own rulemaking authority, granted by the Clean Air Act to establish its own fuel efficiency standards, and flexed that muscle by making the deal with the four automakers. The Trump administration will attempt to revoke that decades-old independent authority, but legal experts question whether it has the authority to do so.

“There is nothing under the Clean Air Act that allows the EPA to revoke a waiver that was given to the state,” said Margo Oge, director of the EPA’s Office of Transportation and Air Quality from 1994 to 2012. “They cannot do that, in my view, based on 20 years managing the program.”

California earned Trump’s ire in July with its deal with Ford, Honda, BMW and Volkswagen to meet stricter fuel efficiency standards – an end-run around the Trump administration’s efforts to relax standards developed during the Obama administration.

Trump lashed out at Ford in a series of tweets.

The Trump administration maintains fuel efficiency mandates make cars more expensive and harm the automotive industry, its workers and consumers.

Environmentalists say the mileage standards are necessary to reduce greenhouse gas emissions and will benefit consumers by saving money on gasoline expenditures.

California is the only state with a waiver to create its own fuel efficiency standards, largely because of the state’s unique air quality problems and its intimate involvement with the crafting and passage of the Clean Air Act during the Richard Nixon administration.

California Attorney General Xavier Becerra has already pledged to fight the revocation in court if and when it occurs.

“California will continue its advance toward a cleaner future,” the attorney general said last week. We’re prepared to defend the standards that make that promise a reality.”

— By Matthew Renda