WASHINGTON (AP) — 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, confronting a state that has repeatedly challenged the administration’s environmental rollbacks.

The Environmental Protection Agency was preparing paperwork for the White House for the move, meant to help the administration set a single, less rigorous mileage standard enforceable nationwide, 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 greenhouse gas emissions and 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.