The Trump administration is planning a proposal to block California regulators from enforcing their own emissions standards for vehicles sold in the state.
The proposed regulations revamp will also stop the current federal rules aiming to boost fuel efficiency into the next decade.
The proposal would also freeze federal requirements on fuel economy at a fleet-average 35 miles per gallon by 2020, rather than allowing that figure to climb to 50 mpg by 2025 as it is now set to do.
President Donald Trump's administration is advancing a plan to freeze fuel-economy standards for new cars and trucks, and to escalate its fight against California's power to set regulatory standards for the entire USA auto market, according to people familiar with the matter. The National Highway Traffic Safety Administration will also look to limit California's regulatory powers by barring it from regulating greenhouse gases.
The proposal is still in the final stages of a broad interagency review led by President Donald Trump's Office of Management and Budget, but these major elements of the plan were not expected to change, the people said. Jerry Brown did not respond to a request for comment Monday.
California and like-minded states are girding for a legal battle with the Trump administration on whether those states have gone too far in controlling greenhouse gases from automobiles, a prospective case that legal scholars say - barring a last-minute settlement - is sure to reach the U.S. Supreme Court.
The Trump administration proposal will seek to reverse planned hikes in fuel efficiency standards adopted by the Obama administration.
Special provisions in the federal Clean Air Act allow states to either follow the federal requirements or adopt California's vehicle emission regulations. But the state has aligned its rules with those set by the EPA and NHTSA in a so-called national program of clean-car rules.
California and other states have big stakes in Trump's decision and subsequent litigation, as do US and foreign automakers. More than a dozen states follow California's standards, making for a significant part of the country's auto market.
California, for its part, rejects the idea that its 48-year ability to write its own tailpipe emission rules should end.
"We have the law on our side, as well as the people of the country and the people of the world", he said. The revision would also impact California's mandate on electric vehicle sales in the state.
Caught somewhere in the middle are automakers, who in recent months have stressed they would not support freezing the federal targets and want Washington and Sacramento to continue linking their vehicle efficiency goals.
To combat California's well-known smog problems, over the years, the golden state enacted some of the strictest emission standards for motor vehicles in the state, even going as far as requesting a waiver from the EPA to set its own fuel economy standards, which are tougher than what the federal government mandates.
Because states rights are only applicable to women's reproductive health.