The Trump administration may soon reveal a plan, involving the U.S. EPA and NHTSA, that would attempt to completely revoke the authority of California to set its own auto-emissions standards, as well as preempt other states from setting their own rules for vehicle emissions. 

According to a Reuters report from Thursday, citing two people who were briefed on the matter, the administration is planning to submit the plan for final White House regulatory review, which would mean that more details will soon be available for greater scrutiny within the next few weeks. 

Four major automakers—Ford, Volkswagen, BMW, and Honda—in July effectively sided with California and made a voluntary agreement with California to keep with its stricter emissions standards and not challenge its regulatory authority. 

The Justice Department Friday launched an antitrust investigation into those four automakers over that agreement. According to the Wall Street Journal, the Justice Department's concern centers around how the companies had negotiated with one another, independent of a regulator.

Friday a federal appeals court is also due to hear arguments in California vs. EPA. That separate case challenges what effectively started this situation that splintered automakers and allied more states against the federal government: the EPA’s decision itself to withdraw the Obama Administration’s existing Mid-Term Evaluation of federal greenhouse-gas standards for 2022-2025, claiming they were too stringent. 

President Barack Obama sits in 2017 Chevrolet Bolt EV electric car at Detroit Auto Show, Jan 2016

President Barack Obama sits in 2017 Chevrolet Bolt EV electric car at Detroit Auto Show, Jan 2016

GM has not allied with California for stricter standards, despite its plan to bank a lot of its future on the electric vehicles that California is encouraging. Its CEO Mary Barra met with President Donald Trump Wednesday, and Barra called the meeting “productive and valuable”—although that comment might have related to ongoing trade or union/labor issues rather than vehicle efficiency. 

Trump has been extremely critical of both GM or Ford in recent weeks. He last month criticized Ford particularly for not fighting California regulators, saying that Henry Ford would be disappointed. And last week, he accused GM of moving “major plants to China” prior to his tenure as President.

“All-electric is not going to work,” Trump said late last year, of Barra’s plan to push toward more electric vehicles. “It’s wonderful to have it as a percentage of your cars, but going into this model that she’s doing I think is a mistake.”

California represents 12 percent of the nation’s new-vehicle sales. Including all the states that comply with California’s ZEV program and its electric vehicle mandate, the number is greater than 30 percent.

This piece was updated after its original publication to add news of a reported antitrust probe potentially affecting Ford, Honda, BMW, and Volkswagen.