A former foreign policy adviser on the Trump presidential campaign who lied to authorities in the special counsel’s Russia investigation must surrender Monday to begin a 14-day prison term, a Washington federal judge ruled Sunday.

George Papadopoulos, who was sentenced in September, had urged the court to delay the start of his prison sentence pending the outcome of a challenge to the power of the special counsel, Robert Mueller III, in the U.S. Court of Appeals for the D.C. Circuit.