Three consumer groups this week sent a letter to Gov. Jared Polis asking for a boycott of nine automobile manufacturers in state vehicle purchases because they support the Trump Administration’s effort to nullify California’s strict automobile emissions standards.

“Consumer Federation of America, Consumer Action and Consumers for Auto Reliability and Safety believe that by boycotting these nine automakers from state fleet purchases you can send a signal and show them that you do not condone the fact that they are actively working to roll back progress on the climate crisis and air pollution,” the groups wrote in the letter dated Feb. 12.

In November, California sued the administration for revoking the state’s longstanding waiver to set its own emissions standards for automobiles, which historically were more stringent than the federal government’s. Twenty-two other states joined California in its suit, including Colorado. Colorado is also one of the 13 states that has taken advantage of the Clean Air Act’s provision to adopt California’s emission standards.

Citing the fact that California is home to seven of the 10 worst cities in the country for air pollution, the state’s Air Resources Board argued that “California has a serious smog problem, exacerbated by climate change, and still needs stricter-than-federal standards to address it and many other climate and air quality issues. In fact, air quality in many parts of the state faces major threats as climate change worsens, leading to more smog, more wildfires, and increased risk. Climate change itself poses a severe threat to Californians.”

The consumer groups’ letter, sent to each of the 22 states joining the lawsuit, asks the governors to refrain from acquiring vehicles from General Motors, Fiat-Chrysler, Toyota, Nissan, Subaru, Hyundai, Kia, Mazda and Mitsubishi in their state fleets. PBS reports that Isuzu, Suzuki, Maserati, McLaren, Aston-Martin and Ferrari, have also sided with the administration.

Conor Cahill, a spokesperson for Polis, said that the governor has worked to increase the use of zero-emission vehicles and reduce overall emissions from the transportation sector. “Rather than infringing upon state’s rights, the Trump Administration should be working with us on solutions to an issue that has a long history of bipartisan consensus and industry support,” he said.

Cahill added that the Polis Administration is “disappointed” with the automakers who sided with the White House, but Colorado’s focus is “leading by example”. 

Editor’s note: This story has been updated with comments from the Polis Administration.