The Texas attorney general has filed a petition in federal court to block new air pollution rules.
GOP presidential candidate Gov. Rick Perry has made blocking Environmental Protection Agency rules a major campaign issue. Attorney General Greg Abbott had already filed one suit to block rules designed to reduce greenhouse gas emissions.
In the petition, Abbott asked the U.S. Court of Appeals in Washington to review the new clean air regulations. A petition to block is expected Wednesday.
The EPA issued the rules on July 27. They require states to reduce emissions of sulfur dioxide and nitrogen oxide, which mostly come from coal-fired power plants. One of the largest Texas electricity producers threatened to shut down two plants and lay off hundreds of workers if the rules were enforced.