The Supreme Court on Thursday temporarily cleared the way for construction of a 300-mile pipeline capable of carrying two billion cubic feet of natural gas daily from northern West Virginia to southern Virginia.
In lifting a stay on the pipeline, the court issued a brief order that gave no reasons, which is typical when the justices act on emergency applications. The order was provisional, and the case will move forward in the lower courts.
The Mountain Valley Pipeline, which has cost more than $6 billion, has been the subject of years of legal challenges from environmental groups and is nearing completion.
A provision concerning the pipeline was tucked into legislation enacted in June to raise the debt limit. The provision, championed by Senator Joe Manchin III, Democrat of West Virginia, barred most legal challenges to the construction and said challenges to the provision itself must be brought in a federal appeals court in Washington.
The United States Court of Appeals for the Fourth Circuit, in Richmond, Va., nevertheless issued orders this month temporarily blocking the remaining construction.
Backers of the pipeline embraced the Supreme Court’s decision, expressing relief that construction would continue.
Patrick Morrisey, West Virginia’s attorney general, described the pipeline as crucial.
“The Mountain Valley Pipeline is vital to the survival of American energy independence and affects thousands of jobs in West Virginia,” Mr. Morrisey said in a statement. “Its completion is also critical to our national security.”
Environmental groups denounced the ruling, calling the pipeline “destructive” and adding that they would make every effort to stop it.
“The Mountain Valley Pipeline is a threat to our water, our air and our climate,” Jamie Williams, president of the Wilderness Society, one of the groups challenging the pipeline, said in a statement.
Lawyers for the project, led by Donald B. Verrilli Jr., who served as the U.S. solicitor general in the Obama administration, filed an emergency application in the Supreme Court asking the justices to lift the appeals court’s stay and allow the construction to proceed.
Under Supreme Court precedent, Congress may not direct the outcomes of particular cases. But it may change the law more generally, even retroactively, and even when it effectively ensures that one side will win. That is what Congress did in connection with the pipeline, the project’s lawyers argued.
“Congress has exercised its constitutional prerogatives to amend retroactively the relevant legal standards and processes in order to hasten completion of an infrastructure project it considers vital to the national interest,” they wrote, adding that the Fourth Circuit was thus powerless to block the pipeline.
“Time is of the essence,” the lawyers wrote. “Maintaining the stay orders for even a few additional weeks will prevent the pipeline from being placed in service by the end of the year as currently planned.”
They added: “The failure to complete the pipeline this year will deprive its shippers — including natural gas and electric utilities, gas producers and others — of critical additional gas transportation capacity for the upcoming winter peak demand season, contributing to natural gas shortages and price spikes, harming the general public and businesses alike.”
Mr. Manchin filed a supporting brief in the Supreme Court, saying that the provision was necessary and constitutional. “Faced with what seems to be unending litigation, and with no end in sight, Congress took matters into its own hands,” he wrote.
The Biden administration also filed a brief urging the justices to allow the construction to proceed, saying that the new law was constitutional and that the Fourth Circuit lacked jurisdiction over the case.
Environmental groups challenging the pipeline had asked the court to keep the Fourth Circuit’s freeze in place, arguing that Congress had overstepped in trying “to decide these cases for itself.”
Even as the Supreme Court announced its decision, lawyers in the case were before the Fourth Circuit, arguing about the constitutionality of Mr. Manchin’s provision.
A judge paused to announce the court’s decision, according to a person in the courtroom.