The U.S. Supreme Court refused U.S. natural gas company Spire Inc.’s request to stay a lower court decision that vacated a federal permit to operate the company’s STL pipeline in Missouri.

Spire has warned that the shutdown of the 65-mile (105-km) pipeline could cause gas outages for as many as 400,000 in St. Louis this winter.

The company, however, already has permission from the U.S. Federal Energy Regulatory Commission (FERC) to continue operating the pipe through at least mid-December as Spire and FERC figure out what to do about the permit problem.

“While we are disappointed by today’s decision ... STL Pipeline will continue to operate under the currently effective emergency certificate issued by the [FERC],” Scott Smith, president of Spire STL Pipeline, said in a statement.

FERC issued the temporary emergency certificate to operate after the U.S. Court of Appeal for the District of Columbia Circuit vacated in June the certificate FERC issued for the roughly $285 million pipe in 2018.

Spire said it will ask the Supreme Court to review the appeals court decision to vacate its permanent certificate order by Dec. 6.

The appeals court said the problem with the 2018 certificate was that FERC found a market need for the pipeline despite only one gas supplier, an affiliate of the line’s operator, committing to use it.

“FERC can determine the appropriate conditions for a temporary certificate and ensure continuity of service for the people of St. Louis,” said the Environmental Defense Fund (EDF), noting “FERC is poised to issue another temporary certificate to ensure reliability.”

EDF brought the case that overturned the FERC permit.

The line, designed to deliver up to 400 MMcf/d of gas, began operating in November 2019.