WASHINGTON — Senator Mitch McConnell, Republican of Kentucky and majority leader, is urging governors to defy President Obama by refusing to implement the administration’s global warming regulations.

In an op-ed article published Wednesday in The Lexington Herald-Leader with the headline, “States should reject Obama mandate for clean-power regulations,” Mr. McConnell wrote: “The Obama administration’s so-called ‘clean power’ regulation seeks to shut down more of America’s power generation under the guise of protecting the climate.” He added, “Don’t be complicit in the administration’s attack on the middle class.”

As Mr. Obama pushes an aggressive climate change agenda, the Environmental Protection Agency has proposed regulations to slash greenhouse gas emissions from coal-fired power plants, the nation’s largest source of planet-warming pollution. The rules, which the E.P.A. expects to be final this summer, would require each state to submit a plan detailing how it would cut coal-fired power plant pollution. Once implemented, the plans could lead to the closing of hundreds of coal plants, in what the administration says will be a transformation of the nation’s energy economy away from fossil fuels and toward sources like wind and solar.

States that rely heavily on coal production or coal-fired electricity are wary of the plan, which could ultimately freeze demand for coal. Already, 12 states, including Mr. McConnell’s home state, have filed lawsuits opposing the plan and at least a dozen more are expected to file similar suits.