The U.S. Department of Justice is challenging Vermont’s climate superfund law in court.

A complaint filed Thursday afternoon in the U.S. District Court of Vermont targets the law, arguing that the federal Clean Air Act and federal government’s power over foreign affairs preempt the state law, making it unconstitutional. The Department is asking the federal court to stop the law from being enforced.

“I’m always proud to represent Vermont, and I look forward to doing so in this case,” Vermont Attorney General Charity Clark wrote in an email. She also noted that the Department Justice has yet to formally serve the state with the lawsuit.

Thursday’s complaint follows an April executive order from President Donald Trump that tasked the U.S. Attorney General with exploring ways to block Vermont, New York and California’s climate laws.

The climate superfund law, Act 122, applies a polluters-pay framework, like a federal hazardous waste superfund, to the costs of climate damages — like flood recovery. Vermont was the first state in the nation to adopt this framework for climate disasters. In December, New York followed and adopted its own climate superfund bill.

The Justice Department also filed lawsuits against three other states, targeting actions that hold oil and gas companies accountable for the costs of climate damages, specifically New York state’s climate superfund, and Hawaii and Michigan’s lawsuits against fossil fuel companies, according to a Justice Department press release.

In its release, the Justice Department argues that these state actions “unreasonably burden domestic energy development” and put the US in a “national energy emergency.”

“I will just note that there is no national energy emergency,” Clark told VTDigger in April, after Trump issued the executive order. “American energy is at an all time high, and state laws are not a threat to American energy,” she said.

Make Polluters Pay, a national campaign that promotes laws and lawsuits that hold fossil fuel companies responsible for the costs of climate damages, called the four federal lawsuits against the states as “political theater, plain and simple,” as Cassidy DiPaola, the communications director said in a press release.

“This is not a surprise,” Paul Burns, the executive director of Vermont Public Interest Group said in a press release. VPIRG was instrumental in the construction and passage of the climate superfund law. “This lawsuit is one more instance of our billionaire president holding the fossil fuel industry in a warm embrace by giving Vermonters the finger.”

When Trump first filed his executive order targeting the Vermont law, Pat Parenteau, an emeritus professor at Vermont Law School’s Environmental Law Center, explained to VTDigger that the government was likely to argue that the federal Clean Air Act preempts the state law. But those claims ring hollow, he explained, since the federal law deals with the source of emissions, not payments for past emissions.

In April, Parentau explained that Vermont should be ready for a long legal battle, saying that the federal government and fossil fuel industry have deep pockets to prolong these lawsuits that aim to “bleed its opponents dry.”