In a letter to President Barack Obama released Monday, senators Joe Manchin of West Virginia, Joe Donnelly of Indiana, Heidi Heitkamp of North Dakota and Mary Landrieu of Louisiana said the EPA should revise its rule setting a limit of 1000 pounds of carbon dioxide emissions per MWh for coal-fired power plants.

“EPA’s proposed performance standards for new units will require coal-fuelled power plants to meet the same standards as new gas-fired plants,” the senators wrote.

They argued that the EPA should have different standards based on fuel type and the proposed rule would effectively ban new coal-fired power plants from being built without carbon capture and sequestration technology.

“Such a requirement is unprecedented under the Clean Air Act and will have the unfortunate effect of preventing construction of new coal plants or the upgrading of exisiting sources,” they wrote.

“Such a consequence could actually block potential GHG emissions reductions, endanger our electricity supply, and harm our economy. We urge you to consider an alternative approach.”

EPA is in the process of finalizing the proposed rule and has received more than 2 million comments on it.

The agency might not meet its April 13 decision deadline and, according to a report late last week by the Washington Post, may be looking to issue a separate, less-stringent standard for coal-fired power plants.

EPA has faced significant opposition to the new rule, mostly from Republicans, making this Democratic authored letter notable.

Manchin released a statement on Monday criticising the government’s tough stace on greenhouse gas emissions.

“I have said again and again that government needs to work as an ally, not as an adversary, when it comes to developing our nation’s energy policy,” Manchin said in a statement.

“[The regulation] is yet another example of EPA overreach by the Obama administration.”

“Not only would this rule have a devastating effect on our coal production, this rule would endanger the reliability and sustainability of our electricity supply.”

The senators urged the EPA to set supercritical coal generation as the performance standard for new coal-fired power plants.