Texas Attorney General Greg Abbott fired the opening legal volley in another round of ongoing battles between the Lone Star State and the Environmental Protection Agency.

The State of Texas filed the opening brief challenging the EPA’s Tailpipe Rule, which attempts to limit the amount of greenhouse emissions from motor vehicles, claiming that the rule is unlawful, and their greenhouse gas regulations violate the federal Clean Air Act.

The Tailpipe Rule limits emissions from vehicles produced for the 2012 model year and all models afterward, and requires a car manufacturer to maintain a fleet average of 35.5 miles per gallon for cars and light-duty trucks. Lower-volume auto manufacturers such as Maserati, Aston Martin, and the like will be required to buy credits from larger manufacturers who exceed the rule’s basic guidelines until 2017, when all manufacturers will be required to be compliant with the regulation.

The brief was filed on behalf of nine states with the U.S. Court of Appeals for the D.C. Circuit, and argues that the high costs imposed on businesses and consumers with the Tailpipe Rule is in violation of the Clean Air Act, which states that administrators of the EPA must consider the costs being passed on due to their rules.

The brief also claims that the Clean Air Act was violated by the Tailpipe Rule because the Clean Air Act outlines that the EPA is only permitted to regulate air pollutants that pose a danger to human beings’ health and welfare, and the claim that greenhouse gas emissions endanger human health and welfare is “both incorrect and not authorized by law.”

Former EPA Administrator Stephen Johnson has said that the Tailpipe Rule results in an “unprecedented expansion of EPA authority, and has “a profound effect on virtually every sector of the economy and touches every household in the land,” according to the Texas Attorney General’s office.

Other states joining in the brief are Alabama, North Dakota, Georgia, Mississippi, South Dakota, South Carolina, Virginia, and Nebraska. Texas is currently challenging all six of the EPA’s greenhouse gas regulations in federal court.