The Boston-based 1st U.S. Circuit Court of Appeals turned back the emergency appeal, though it said it expected the lower court judge to act quickly to clarify his order and would keep considering the issue.

A federal court in Massachusetts that has become a popular destination for lawsuits challenging U.S. President Donald Trump's second-term agenda has moved to prevent litigants from engaging in "judge shopping" by suing in two of its courthouses that each only have one judge.