FILE PHOTO: Several freight trucks drive down Highway 80 through Rodeo, California, U.S. December 6, 2022. REUTERS/Brittany Hosea-Small/File Photo

By Jonathan Stempel and Bhargav Acharya

(Reuters) -The U.S. government said on Friday it sued California to stop the state from enforcing stringent emissions standards for heavy-duty trucks that President Donald Trump recently declared void.

In complaints filed this week in two federal courts, the U.S. Department of Justice said federal law preempts the California Air Resources Board from enforcing various emissions rules governing heavy-duty trucks and engines.

These include the Clean Truck Partnership, a 2023 initiative with manufacturers designed to advance California's goal of lowering emissions, while giving the truckmaking industry flexibility to meet emissions requirements.

The Justice Department sued after a House of Representatives committee said it recently learned that staff at the California Air Resources Board won't let auto manufacturers bring vehicles to market unless they comply with California's preempted standards.

"This ongoing defiance of federal law must stop," the department said. California's rules governing light-duty vehicles are also preempted, the department added.

The California Air Resources Board declined to comment, while the office of California's Governor Gavin Newsom did not immediately respond to requests for comment.

Newsom, a Democrat, has long promoted tough emission standards, as well as the sale of electric vehicles, to help fight climate change.

California has long had power under the federal Clean Air Act to set tighter pollution limits than federal law requires, and received more than 100 waivers under that law since 1970.

But the Justice Department said the Republican Trump's signing in June of congressional resolutions curbs California's power, including by voiding a waiver allowing the Clean Truck Partnership.

"President Donald Trump and Congress have invalidated the Clean Air Act waivers that were the basis for California’s actions," said Adam Gustafson, acting assistant attorney general for the Justice Department's environment and natural resources division. "CARB must respect the democratic process."

The new lawsuits are intended to help Trump end California's push for electric vehicles, level the regulatory playing field and promote consumer choice, the department added.

Both lawsuits were filed as motions to intervene in existing federal cases challenging California's emissions standards, including the Clean Truck Partnership.

One case was filed on Monday in Sacramento, California by four large truck makers--Daimler, International Motors, Paccar and Volvo .

The other was filed in December in Rockford, Illinois by the American Free Enterprise Chamber of Commerce.

(Reporting by Jonathan Stempel in New York, Bhargav Acharya in Toronto and Andy Sullivan in Washington, D.C.; Editing by Caitlin Webber, Rod Nickel and Diane Craft)