The Trump administration has launched a multipronged legal assault on an agreement California struck with four carmakers in defiance of the president’s plan to ease national standards on tailpipe emissions.

Lawyers from the Transportation Department and Environmental Protection Agency on Friday sent a letter to California’s top air-pollution regulator, urging the state to abandon its pact with the automakers and warning that actions to carry out the agreement “appear to be unlawful and invalid.”

Separately, the Justice Department has opened an antitrust probe into the deal, in which four automakers agreed on compromise tailpipe emissions requirements with California. The administration is also preparing to formally strip California’s authority to set auto efficiency regulations that are tougher than the federal government’s, according to people familiar with the matter.

The actions amount to a significant escalation of the conflict between the Trump administration and Sacramento over environmental protections. It comes as automakers have urged the administration to moderate its rollback of emissions levels, arguing that a battle with California over the state’s regulatory powers would leave the industry with uncertainty over the critical standards for years.

Automakers want to avoid splitting the market with two different standards — a federal mileage requirement in most states versus more stringent rules in more than a dozen states that adhere to California’s standards and account for more than a third of U.S. auto sales.

After talks with California and the Trump administration faltered, the California Air Resources Board announced in July an accord with the Ford Motor, Honda,  BMW and Volkswagen on tailpipe greenhouse gas emissions regulations.


The carmakers had agreed with California’s clean-air regulator to boost the fuel efficiency of autos sold in the U.S through 2026, defying a Trump administration proposal to ease mileage requirements enacted during the Obama administration.

Carmaker Response

Ford and Honda said they would cooperate with the Justice Department, while VW said it was “in regular contact with U.S. authorities on a number of matters.” BMW of North America said it looked forward “to responding to the Department of Justice to explain the planned CARB framework agreement and its benefits to consumers and the environment.”

In one of the letters seen by Bloomberg News, the Justice Department wrote it was concerned that the California agreement may violate federal antitrust laws, noting that the department hadn’t reached any conclusions on the matter. The department proposed a meeting to gather additional information about the emissions agreement and communications between the companies about the pact.

Mary Nichols, chairman of the California Air Resources Board, said the Justice Department was bringing “its weight to bear against auto companies in an attempt to frighten them out of voluntarily making cleaner, more efficient cars and trucks than EPA wants.”

Russ Vought, acting director of the White House’s Office of Management and Budget, defended the Trump administration’s proposed fuel economy standards, saying they would make cars safer and more affordable.

“Unfortunately, California is trying to impose its failed policies on the rest of the country,” Vought said in a statement. “Even worse for Americans on the road, a handful of irresponsible auto makers are aiding California’s radical agenda that will hurt every one of us.”

Barbara McQuade, a law professor at the University of Michigan and former U.S. attorney in Detroit, questioned the Justice Department move.

“It raises a red flag as to whether this is a valid exercise of antitrust laws or an effort advance the Trump administration’s policies to roll back environmental protections, and if so that would be an abuse of DOJ‘s power,” McQuade said.

–With assistance from Chester Dawson and David R. Baker.