WASHINGTON (Reuters) - The state of California filed a lawsuit on Friday seeking to force two federal agencies to provide data they used to justify rolling back landmark Obama-era vehicle emission standards, accusing the Trump administration of “willfully withholding” information.

FILE PHOTO: Morning commuters travel in rush hour traffic towards Los Angeles, California, U.S., March 20, 2019. REUTERS/Mike Blake

In a lawsuit filed in U.S. District Court in Washington, D.C., California Attorney General Xavier Becerra said the National Highway Traffic Safety Administration and Environmental Protection Agency failed to respond to a Freedom of Information Act request seeking data and analysis backing their proposal to freeze federal vehicle emission standards at 2020 levels through 2026.

In addition to weaker fuel efficiency standards, the Trump administration proposal would strip California of the ability to impose stricter rules, which a dozen other states have adopted.

In 2011, California had agreed to harmonize its emissions with the Obama administration’s vehicle emissions requirements through 2025.

“This lawsuit will break down their silence and secrecy,” said Mary Nichols, chair of the California Air Resources Board. “The public has a right to see all the facts and analysis used to support a rollback that increases oil consumption, hurts consumers, and pumps more air pollution and hundreds of million tons of climate-changing gases into the atmosphere.”

The two federal agencies did not immediately comment.

The Obama-era rules called for a fleetwide fuel efficiency average of 46.7 miles per gallon by 2026, compared with 37 mpg under the Trump administration’s preferred option.

The lawsuit is the latest escalation in the feud between California and the Trump administration over vehicle emission standards.

In February, the White House ended negotiations with California over the plans to freeze fuel rules and pressured automakers to back their efforts.

California and 19 other states demanded the Trump administration abandon its proposal. States sued last year over the EPA’s decision to revisit its January 2017 determination the 2025 rules were feasible.

Automakers like General Motors Co, Ford Motor Co and Toyota Motor Corp oppose a freeze but want requirements reduced to account for changes in oil prices and consumer demand.

The EPA is on track to release final emissions rules by “spring or early summer,” Administrator Andrew Wheeler told reporters on Thursday. Wheeler hopes California will not sue EPA once it releases final requirements, but if it does he suggested California do it quickly “to ensure regulatory certainty.”

Deputy NHTSA Administrator Heidi King said on Friday that dramatically higher fuel efficiency rules can “hinder safety” by raising the price of new, safer vehicles.