California sued the Trump administration Friday to force it to provide data supporting its rollback of Obama-era vehicle emissions standards, which California called "radical."

California’s Democratic Attorney General Xavier Becerra, suing in the U.S. District Court for the District of Columbia, is seeking the release of documents from the Environmental Protection Agency and National Highway Traffic Safety Administration that justify its plan to weaken the fuel efficiency rules.

Becerra claims the Trump administration agencies failed to comply with the state’s Freedom of Information Act request filed in early September 2018 seeking the documents.

“We must demand clean air for our kids, and our country must take immediate action to reduce greenhouse gas emissions,” said California Gov. Gavin Newsom, a Democrat. “Yet, the Trump administration is willfully withholding information on their ill-advised rollback of federal vehicle emission standards because there is simply no science or logic to back up their actions.”

California and 17 other states have already sued the Trump administration for rejecting the Obama administration’s fuel-efficiency rules and beginning the process of weakening them.

Attorneys general of those states accuse the Trump administration of flouting the Administrative Procedures Act by not backing up their policy proposal with proper rationale.

The EPA, along with the NHTSA, last August proposed freezing Obama-era fuel efficiency rules for cars and light trucks, instead of raising them each model year from 2020-2026.

The agencies also proposed revoking a Clean Air Act waiver that California has, and more than a dozen other states follow, allowing it to set vehicle emission standards tougher than federal rules. California and other states are expected to sue the administration again in the coming months, when the Trump administration finalizes its plan to relax the fuel rules and revoke the waiver.

EPA Administrator Andrew Wheeler said Thursday he hoped California would not sue the agency once it finalizes the rollback of the car rules, but predicted “we will go to court.”

“I believe we are on firm legal footing and our standards will be upheld by the courts,” Wheeler said at the Washington Auto Show.

The Trump administration argues the tougher Obama rules, meant to combat carbon emissions from transportation, would make newer cars unaffordable, forcing drivers to use older, less safe, and environmentally unfriendly vehicles.

A freeze in the fuel standards could prevent 1,000 fatalities from crashes annually and save Americans an average of roughly $2,340 for every new vehicle purchased, the Trump administration claims.

But career experts at the EPA disagreed with the NHTSA on the number of deaths that would be avoided by rolling back the fuel efficiency rules, according to internal documents released in August.

Scientists from EPA’s Office of Transportation and Air Quality privately warned that computer modeling used by the NHTSA was flawed and argued that the rollback would actually increase annual traffic fatalities, by an average of about 17 deaths per year.

EPA’s internal analysis found that freezing the Obama rules would cost thousands of jobs, and reduce social benefits by $83 billion from forgone reductions in pollution and carbon emissions.

Legal experts say EPA’s questioning of NHTSA’s methodology will bolster the argument of opponents who say the Trump administration has failed to justify its plan to weaken fuel standards with science-based facts.