A coalition of utilities and industry groups that oppose the regulations petitioned the court to halt their implementation, arguing they will harm the economy and threaten the reliability of the power grid.

The decision deals a blow to environmental groups and the Obama EPA, which announced the cross-state air pollution rule in July.

“Today’s judicial decision temporarily halts implementation of life-saving clean air protections for 240 million Americans pending full review of the facts and the law,” Vickie Patton, general counsel for the Environmental Defense Fund, said in a statement.

“The pollution reductions at stake are some of the single most important clean air protections for children, families and communities across the Eastern half of the United States.”

EPA has said that the regulations will prevent 34,000 premature deaths, 15,000 heart attacks and 400,000 cases of asthma starting in 2014, which would amount to $280 billion a year in health benefits.

“The court’s decision is not a decision on the merits of the rule and EPA firmly believes that when the court does weigh the merits of the rule it will ultimately be upheld,” EPA spokeswoman Betsaida Alcantara said in a statement.

“It is disappointing that the significant public health benefits of the Cross State Air Pollution Rule may be delayed, even temporarily, especially given EPA’s work to utilize the Clean Air Act’s flexibility to  ensure the rule is achievable. EPA will ensure the transition back to the Clean Air Interstate Rule occurs as seamlessly as possible.”

This story was updated on Jan. 3 at 12:54 p.m.