U.S. Senator Shelley Moore Capito, R-W.Va., is once again challenging the Biden administration’s so-called Clean Power Plan 2.0.

Capito, ranking member of the Environment and Public Works Committee, joined U.S. Senator John Barrasso, R-Wyoming, ranking member of the Energy and Natural Resources Committee, Tuesday in sending a letter to Environmental Protection Agency Administrator Michael Regan that once again outlines what Capito says is “significant concerns” with the administration’s plan to close fossil-fuel operated power plants across the country.

Doing so will threaten America’s electrical grid on unjustifiable legal grounds, according to Capito.

As currently proposed, Capito said the new EPA rule runs afoul of the Supreme Court’s ruling in West Virginia v. EPA. In that case, the high court ruled 6-3 that the Clean Air Act does not give the federal EPA broad authority to regulate greenhouse gas emissions from power plants.

“We urge the EPA to rescind its Clean Power Plan 2.0 proposal and make affordability, reliability, and the limits of its authorities under the Clean Air Act cornerstones of any future proposal,” Capito and Barrasso wrote in the letter to Regan. “The more time that has passed since the proposal, the more issues with the Clean Power Plan 2.0 have been uncovered.”

Capito said the Biden administration must withdraw the entire Clean Plan Plan 2.0 and start over.

“The flaws we have identified both in the agency’s November request for comments and in the original proposal are so egregious that the EPA must withdraw the Clean Power Plan 2.0 and start over,” Capito and Barrasso added in the letter. “Correction of these serious, foundational deficiencies would require a wholesale rewrite such that any final rule the EPA finalizes would not be a logical outgrowth of the proposal. The only legally permissible course is to develop a new, legally sound proposal and start the rule making again.”

Capito said the EPA plan as currently proposed would threaten the safety and reliability of America’s electrical grid. This, in return, would translate into higher energy costs for ratepayers and reduced reliability. She said low-income and other vulnerable Americans will be disproportionately affected by the plan.

The Biden administration argues the new rules are necessary to protect public health, reduce harmful pollutants and fight climate change.