Washington ? A prominent member of the Supreme Court bar, the small circle of lawyers who regularly appear before the justices, infuriated environmental groups by presenting an argument the groups say is demonstrably incorrect.

The claim a month ago by Washington attorney Carter Phillips that the federal government had changed course in regulating emissions from coal-fired power plants is simply not true and a paper trail of the industry’s own documents proves it, the groups say.

The case, Environmental Defense v. Duke Energy Corp., could determine the fate of an Environmental Protection Agency initiative targeting some of the biggest utilities in the nation. Phillips, representing Duke, is managing partner at the Washington office of the law firm Sidley Austin and has argued more than 50 cases at the Supreme Court.

“These companies are bent on getting away with 20 years of illegal pollution by trying to deceive the Supreme Court,” said Natural Resources Defense Council clean air director John Walke, who is a former EPA attorney.

Utility industry attorney Scott Segal jumped to Phillips’ defense, saying that “for these environmental groups to go after one of the best lawyers in the country is a travesty.”

The government enforcement action against Duke is one of more than a dozen brought by the Clinton administration in 1999 and 2000.

It is aimed at forcing power companies to install the latest pollution-control equipment on aging coal-fired plants that were renovated so they could be operated longer hours.

On Nov. 1, Phillips told the justices: “Our basic argument is that all along” EPA interpreted the regulatory requirements “in a certain way. And then 19 years later, they reversed course” and suddenly sued the companies.

The environmental groups say internal industry documents clearly show that Duke understood long ago the EPA was interpreting the requirements in the same way it did in 1999 when the government went to court.

Some of the documents are part of the record before the Supreme Court and all were brought to light in lawsuits against Duke and other utilities.