EPA accused of reversal on emissions

Johnson's decision also blocked more than a dozen other states, including Massachusetts and Rhode Island, that wanted to follow California's lead and regulate greenhouse gas emissions from cars and trucks. It was applauded by the auto industry and supported by the White House, which has adamantly opposed mandatory caps on greenhouse gas emissions.

Johnson has defended the December decision as his alone. He has refused to say whether there was White House pressure.

Although California had never previously been fully denied a waiver request under the Clean Air Act, Johnson justified denying this one on the basis that California is not alone in suffering the effects of global warming and therefore doesn't have a compelling need for its own greenhouse gas standards. EPA spokesman Jonathan Shradar dismissed the report by the committee, chaired by Representative Henry Waxman, Democrat of California, as "nothing new."

"Administrator Johnson was presented with and reviewed a wide range of options and made his decision based on the facts and the law," Shradar said. "Distraction-oriented, political tactics of the committee will not keep EPA from moving forward, tackling tough issues and putting into place the most health-protective standards ever."

Shradar did not respond when asked whether it was true Johnson initially supported fully or partially granted the waiver request.

California's law would have forced automakers to cut greenhouse gas emissions by 30 percent in new cars and light trucks by 2016, beginning with the 2009 model year.

In the course of its investigation the committee issued three subpoenas, received more than 27,000 pages of documents and deposed eight EPA officials.

The committee found, as has been previously reported, that the EPA's career staff was unanimously in favor of at least partly granting the California waiver and advised Johnson that any other decision was unlikely to stand up in court.

The most explosive new evidence came from a deposition with EPA associate deputy administrator Jason Burnett.