The Justice Department asked the Supreme Court to intervene on Monday in its fight over California’s voter rolls, seeking an emergency order separating mail ballots associated with more than 20,000 suspected noncitizens one day before Election Day.

Solicitor General D. John Sauer asked the justices to order California to set those ballots aside immediately while the court weighs whether to keep them separate during the government’s appeal. The request follows defeats before a federal district judge and a divided appeals court.