"Only this administration has questioned the law," said Connecticut Attorney General Dick Blumenthal, who attended a media briefing led by the Clean Air Trust, the U.S. Public Interest Research Group and Natural Resources Defense Council.

In mid-May Vice President Dick Cheney ordered a review of the two-decades old new source rules as part of the White House energy task force recommendations for a new energy policy.

Electricity generators and oil refiners have complained to the Bush White House about interpretation of the rules.

The Clinton administration had sued major power companies in the Midwest and South for violating new source rules, blaming them for operating 51 plants illegally by pumping tons of nitrogen oxide, sulphur dioxide and other pollutants into the air, which eventually sweep into the Northeast.

Now, environmentalists are worried the Bush review of clean air rules will turn back the clock on enforcement.

"Big electric power companies and others have violated the Clean Air Act, and they're getting away with it, like outlaws," said Frank O'Donnell, executive director of Clean Air Trust.

Blumenthal said dirty air has killed 299 people in his state, leading him to sue power companies for billions in damages for healthcare costs and environmental destruction.

He said currently the state has joined in four suits against power firms.

New York, New Jersey and Connecticut have sued Ohio Edison in a case expected to proceed to trial in the spring of 2002, he said.

Massachusetts, Rhode Island, New Hampshire, Vermont, Maryland, New York, New Jersey and Connecticut have sued Columbus, Ohio-based American Electric Power.

New York and Connecticut have sued Richmond, Va.-based Dominion Resources, and New Jersey, New York and Connecticut have also sued Cincinnati, Ohio-based Cinergy.

There was no comment from the companies being sued.