WASHINGTON — For three decades, the federal government has allowed California to plot its own course in its war against air pollution.
But on Wednesday, the Bush administration sided with DaimlerChrysler and the General Motors Corp. in a lawsuit charging that California had overstepped its authority in revising its "zero emissions" vehicle rule last year.
"This is an impermissible intrusion into the federal government's jurisdiction," said Chet Lunner, a spokesman for the U.S. Department of Transportation, explaining why the federal government intervened in the case before the U.S. 9th Circuit Court of Appeals in San Francisco.
State officials and environmentalists said the action was significant because it marked a departure from the federal government's long-held practice of supporting California's efforts to clean up its smoggy air.
"I am disappointed that the federal government would intervene with our efforts to protect our air quality," Gov. Gray Davis said.
California is the only state in the nation that has the right under federal law to set its own standards, and the state has the nation's toughest pollution regulations.
"The federal government has never stood in California's way before," said David Doniger, policy director for the Natural Resources Defense Council's Climate Center.
In June, a federal judge temporarily blocked California from moving ahead with the revisions while the case was being heard. These revisions would give auto companies options in how they meet their quotas for "zero emissions" vehicles, including granting credits for hybrid vehicles, which are powered by a combination of a gasoline engine and electricity.
In its brief, the federal government argued that granting credits for hybrids "preempted" the federal government's sole authority to set fuel-efficiency standards for automobiles, because the criteria for hybrids are defined in reference to fuel-economy standards.
State officials and environmentalists said that the Bush administration action is likely to bolster the companies' legal effort, which has caused havoc with a 12-year-old California program designed to put smog-free electric cars on the freeways.
"It's disappointing," said Sandra Michioku, a spokeswoman for the state attorney general's office. "We believe the federal government should work with California to meet clean-air requirements imposed on the state."
Environmentalists criticized the government for the latest in a string of Bush administration actions that take the side of industry in disputes over environmental policy. Many top officials in the administration have worked for energy interests in the past; Andrew H. Card Jr., the White House chief of staff, formerly was a top lobbyist for the auto companies.
Doniger said the Bush administration sent a clear message in its brief: "Given the choice between clean air in California and car makers, they choose car makers. Given the choice between states' rights and car makers, they choose car makers."
Spokesmen for the automakers said company officials had not had time to read the brief, which was filed late in the day, and would have no specific comment.
"We appreciate the support of all of the organizations that have filed briefs on our behalf," said Kathy Graham, a spokeswoman for DaimlerChrysler.