The governor put the federal government on notice six months ago saying such a lawsuit would be filed if the US EPA continued to delay action on California's request for authority to regulate greenhouse gas emissions for cars and light trucks sold in the state.

Fourteen other states are expected to join California's lawsuit later in the day, according to the governor.

"California has a long and proud history of leadership in reducing pollution and fighting for clean air for our residents. And we are upholding that tradition today by filing a lawsuit against the federal government that takes a big step forward in the battle against global warming," said Schwarzenegger.

"California is ready to implement the nation's cleanest standards for vehicle emissions, but we cannot do that until the federal government grants a waiver allowing us to enforce those standards," he said.

"Our air quality, our health and our environment are too important to delay any longer, and it is not just the people of California who are waiting. Those states that want to follow our lead cannot do so until federal permission is granted," said the governor.

Following the filing of California's lawsuit against the US EPA, 14 states will be announcing that they are joining California as interveners in the lawsuit. These states include Massachusetts, New York, Arizona, Connecticut, Illinois, Maine, Maryland, New Jersey, New Mexico, Oregon, Rhode Island, Vermont, Washington and Pennsylvania.

Under the Federal Clean Air Act, California has the right to set its own tougher-than-federal vehicle emission standards as long as it obtains a waiver from the EPA.

The original request for a waiver of federal preemption of California's Motor Vehicle Greenhouse Gas Emissions Standards was made by the California Air Resources Board (ARB) on Dec. 21, 2005.The waiver, allowing California to enact and enforce emissions standards to reduce greenhouse gas emissions from automobiles, was requested after the ARB developed regulations based on a 2002 California law.

That law required California to establish new standards for motor vehicle greenhouse gas emissions beginning in model year 2009. The ARB-adopted regulations will phase in and ramp up over eight years to cut global warming emissions from new vehicles by nearly 30 percent by model year 2016.

By implementing these standards, California would be eliminating greenhouse gases equivalent to taking 6.5 million cars off the road by the year 2020. If all the other states with similar plans follow through, that figure will grow to nearly 22 million vehicles and will cut gasoline consumption by an estimated 11 billion gallons a year.

Schwarzenegger has urged President George W. Bush to approve California's request to address global warming.

California's request has been supported by recent judicial decisions. In September, a court decision in Vermont confirmed that states do have the ability to adopt California's motor vehicle greenhouse gas emissions standards. Sixteen states comprising about 45 percent of all US auto sales have adopted, or are in the process of adopting California's standards.