Following up on President Obama’s pledge in June to address climate change, the Environmental Protection Agency plans next week to propose the first-ever limits on greenhouse gas emissions from newly built power plants.

But even before the proposal becomes public, experts on both sides of the issue say it faces a lobbying donnybrook and an all-but-certain court challenge. For a vast and politically powerful swath of the utility industry — operators of coal-fired plants, and the coal fields that supply them — there are fears that the rules would effectively doom construction of new coal plants far into the future.

While details of the E.P.A.’s proposal remain confidential, experts predict that it will include separate standards for carbon dioxide emissions from plants fired by natural gas and by coal. Plants using comparatively clean gas would be permitted to emit perhaps 1,000 pounds of carbon dioxide per megawatt-hour, a ceiling within easy reach using modern technologies.

Coal-fired plants, meanwhile, may be allowed to emit as many as 1,400 pounds per megawatt-hour. But coal is so heavily laden with carbon that meeting even that higher limit would require operators to scrub carbon dioxide from their emissions before they reach the smokestack, and then pump it into permanent storage underground.