Congressional Republicans are vowing to prevent the Environmental Protection Agency from using the Clean Air Act to control pollution that contributes to global warming, underscoring the threat with a proposed deep cut to the agency's budget.

Rep. Ed Whitfield, R-Ky., chair of a House subcommittee on energy and power, said that "Congress intends to reassert itself" in the regulatory process at EPA and the Clean Air Act. He spoke at the start of a hearing Wednesday on a bill that would curtail the EPA's powers. At the same time, the GOP proposed a 17 percent cut in the EPA's budget for next year.