Special counsel Jack Smith urged a federal appeals court Monday to reinstate the classified documents case against former President Donald Trump, saying a judge's decision that dismissed the prosecution was at odds with longstanding Justice Department practice and must be reversed.

Smith's team said U.S. District Judge Aileen Cannon made a grievous mistake by ruling that Smith was unlawfully appointed by Attorney General Merrick Garland. That position, prosecutors wrote in a brief filed with the Atlanta-based appeals court, runs counter to rulings by judges across the country as well as "widespread and longstanding appointment practices in the Department of Justice and across the government."