A divided Supreme Court on Tuesday abruptly halted President Obama's controversial new power plant regulations, dealing a blow to the administration's sweeping plan to address global warming.
In a 5-4 decision, the court halted enforcement of the plan until after legal challenges are resolved.
The surprising move is a victory for the coalition of 27 mostly Republican-led states and industry opponents that call the regulations "an unprecedented power grab."
By temporarily freezing the rule the high court's order signals that opponents have made a strong argument against the plan. A federal appeals court last month refused to put it on hold.
The court's four liberal justices said they would have denied the request.
The plan aims to stave off the worst predicted impacts of climate change by reducing carbon dioxide emissions at existing power plants by about one-third by 2030.
"We disagree with the Supreme Court's decision to stay the Clean Power Plan while litigation proceeds," White House spokesman Josh Earnest said in a statement.Earnest said the administration's plan is based on a strong legal and technical foundation, and gives the states time to develop cost-effective plans to reduce emissions. He also said the administration will continue to "take aggressive steps to make forward progress to reduce carbon emissions."
Appellate arguments are set to begin June 2.
The compliance period starts in 2022, but states must submit their plans to the Environmental Protection Administration by September or seek an extension.
Many states opposing the plan depend on economic activity tied to such fossil fuels as coal, oil and gas. They argued that power plants will have to spend billions of dollars to begin complying with a rule that may end up being overturned.
Attorney General Patrick Morrisey of West Virginia, whose coal-dependent state is helping lead the legal fight, hailed the court's decision.
"We are thrilled that the Supreme Court realized the rule's immediate impact and froze its implementation, protecting workers and saving countless dollars as our fight against its legality continues," Morrisey said.
Implementation of the rules is considered essential to the United States meeting emissions-reduction targets in a global climate agreement signed in Paris last month. The Obama administration and environmental groups also say the plan will spur new clean-energy jobs.
Environmentalists were stunned by the court's action, which they stressed did not reflect a decision on the relative strength of the Obama administration's case.
"The Clean Power Plan has a firm anchor in our nation's clean air laws and a strong scientific record, and we look forward to presenting our case on the merits in the courts," said Vickie Patton, a lawyer for Environmental Defense Fund, which is a party to the case.
California Gov. Jerry Brown called the decision an "arbitrary roadblock" that "undermines America's climate leadership."
To convince the high court to temporarily halt the plan, opponents had to convince the justices that there was a "fair prospect" the court might strike down the rule. The court also had to consider whether denying a stay would cause irreparable harm to the states and utility companies affected.
The unsigned, one-page order blocks the rules from taking effect while the legal fight plays out in the appeals court and during any further appeal to the Supreme Court, a process that easily could extend into 2017.
The Associated Press contributed to this report.