A coalition of 17 U.S. states filed a legal challenge on Wednesday against efforts by President Donald Trump’s administration to roll back climate change regulations, deepening a political rift over his emerging energy policies.

Led by New York state, the coalition said the administration has a legal duty to regulate emissions of the gases scientists believe cause global climate change.

“The law is clear: the EPA must limit carbon pollution from power plants,” New York Attorney General Eric Schneiderman said in a statement announcing the challenge.

Trump signed an executive order last week targeting climate change regulations ushered in by former President Barack Obama, saying they hinder U.S. energy production and jobs without providing meaningful environmental benefits.

The order’s main target was Obama’s Clean Power Plan, a law that would require states to slash carbon dioxide emissions from power plants, but which was never implemented because it was challenged in court by 26 Republican-led states.

Trump’s order directed the Environmental Protection Agency to review the regulation to decide whether to “suspend, rescind, or revise it.” Shortly after, EPA filed a legal motion asking the U.S. Court of Appeals for the District of Columbia Circuit to delay ongoing court proceedings on the regulation to allow for the review.

The New York-led coalition’s motion on Wednesday asked the court to throw out the EPA’s request to delay court proceedings, saying the delay “would waste the substantial resources already expended in this litigation.”

“This case is ripe for decision now, and nothing that EPA has proposed to do obviates the need for this court’s review,” according to the statement.

The coalition includes attorneys general from California, Connecticut, Delaware, Hawaii, Illinois, Iowa, Maine, Maryland, Massachusetts, Minnesota, New Mexico, Oregon, Rhode Island, Vermont, Virginia, and Washington – along with the District of Columbia and a number of smaller localities.