Utah's Sen. Mike Lee and Rep. Jason Chaffetz are trying to repeal a federal plan to reduce haze at eastern Utah national parks from nearby coal-powered plants.
The proposal from the U.S. Environmental Protection Agency would require two coal-powered plants in Utah to cut emissions by installing more pollution controls.
Rocky Mountain Power and the state sued the EPA in September to stop the plan, saying utility customers would bear the $700 million cost of making the changes and a state plan to cut down haze was already improving conditions.
The lawsuit is pending in court, but Lee and Chaffetz introduced a resolution of disapproval in Congress on Tuesday calling for the haze rule to be repealed. The Republicans say the EPA plan is costly and ineffective.
Environmental groups say the plan is needed to cut nitrogen oxide emissions.