A federal appeals court has refused to halt the Obama administration's new clean air standards for power plants while opponents wage a legal challenge.

The federal appeals court in Washington, D.C., on Wednesday rejected an emergency request from 15 states and Peabody Energy Corp. to temporarily block the sweeping plan that would require states to cut carbon emissions from existing power plants.

West Virginia and other coal-reliant states have been leading opposition to the plan, which would mandate a 32 percent cut in emissions nationwide by 2030.

The Environmental Protection Agency and the White House have said they believe the limits are legal and rejected an earlier request to put them on hold.