The U.S. Department of Justice moved in federal court in Minneapolis on Monday to halt a lawsuit that Minnesota Attorney General Keith Ellison filed in state court in June 2020, which alleges that oil giants and a major trade group engaged in a decades-long campaign to deceive the public about the risks of climate change. The government’s filing contends that the state’s legal action improperly encroaches on the federal government’s exclusive authority to regulate greenhouse gas emissions, setting up a direct confrontation over the limits of state consumer protection laws when applied to climate-related claims.

“The Constitution does not tolerate such a conflict,” Justice Department attorneys wrote. “Nor does it allow Minnesota to national its regulatory powers.”

Ellison, a Democrat, immediately pushed back, issuing a statement that accused the administration of abandoning the public interest. “The American people deserve a Department of Justice that fights for us, and it’s a tremendous shame that Trump’s DOJ would rather sell us out to Big Oil,” he said.

Minnesota’s lawsuit names ExxonMobil, Koch Industries, the American Petroleum Institute, and Flint Hills Resources, a Koch subsidiary, and alleges violations of state consumer fraud and deceptive trade practices laws. At least 15 other states have filed similar actions, including Massachusetts, New York, and Rhode Island.

Messages left with ExxonMobil, Koch Industries, and the American Petroleum Institute were not immediately returned Monday. When the lawsuit was originally filed, an ExxonMobil spokesperson called it “baseless,” and the American Petroleum Institute said the industry “provides reliable energy to U.S. consumers while substantially reducing its environmental footprint.”

The DOJ filing is the latest move by the Trump administration to roll back federal climate regulations. In February, the Environmental Protection Agency finalized a rule rescinding the 2009 endangerment finding that had determined carbon dioxide and other greenhouse gases threaten public health and welfare, undoing the central legal basis for U.S. emissions rules.

The legal dispute is the latest flashpoint between the Trump administration and Minnesota officials. Tensions have simmered since January, when federal immigration officers killed two Minneapolis residents during a crackdown, and intensified in April when federal agents conducted searches connected to an investigation into publicly funded social programs for children.