WASHINGTON — The Trump administration is moving forward with a proposal to revoke part of California’s authority to set its own automobile gas mileage standards, a government official said Thursday, in another confrontation with a state that has repeatedly challenged environmental rollbacks.

The Environmental Protection Agency was preparing paperwork for the White House that would set a single national standard for fuel economy, according to the official, who is familiar with the regulatory process and spoke on condition of anonymity because the plan has not been made public.

President Donald Trump has pushed for months to weaken Obama-era mileage standards nationwide and has targeted California’s decades-old power to set its own mileage standards as part of that effort.

Administration moves to rescind authority that Congress granted probably would end up in court. When President George W. Bush challenged California’s mileage-setting ability, California fought it. The Obama administration subsequently dropped the Bush effort.

The Trump plan would have to be posted in the Federal Register and would be subject to public comment.

His administration has tried to ease or remove scores of environmental regulations that it regards as unnecessary and burdensome. The tougher mileage standards were a key part of the Obama administration’s efforts to reduce climate-changing fossil fuel emissions.

California has sued the Trump administration 27 times on environmental matters alone, often as part of a group of states. Counting preliminary injunctions, California has won in court 19 times, said Sarah Lovenheim, a spokeswoman for California Attorney General Xavier Becerra.

EPA officials did not immediately respond to a request for comment Thursday.