A top environmentalist is accusing utility companies of "being bent on getting away with 20 years of illegal pollution by trying to deceive the Supreme Court."
The accusation comes from Natural Resources Defense Council clean air director John Walke, who is a former EPA attorney.
What environmental groups are angry over is an assertion made to the Supreme Court a month ago in a far-reaching clean air lawsuit.
Prominent Washington lawyer Carter Phillips told the court that the federal government had changed course in regulating emissions from coal-fired power plants. Environmentalists say the paper trail proves otherwise.
The government enforcement action against Charlotte-based Duke Energy is one of more than a dozen brought by the Clinton administration.
It is aimed at forcing power companies to install the latest pollution-control equipment. The dispute is over how emissions increases are measured.