WASHINGTON — The Justice Department on Monday asked a federal appeals court to issue an emergency order halting a lawsuit by congressional Democrats that alleges that President Trump has illegally profited from his family business while in office.

In a court filing, the department’s lawyers asserted that Judge Emmet G. Sullivan of the United States District Court for the District of Columbia had committed a series of “clear and indisputable” legal errors in allowing the lawsuit to proceed. The most glaring of them, the department said, was his decision that members of Congress had legal standing to sue the president.

Image The department accused Judge Emmet G. Sullivan of committing a series of “clear and indisputable” legal errors in allowing the lawsuit to proceed. Credit... Charles Dharapak/Associated Press

Judge Sullivan, they argued in a filing to the United States Court of Appeals for the District of Columbia Circuit, wrongly treated a complaint based on novel and flawed legal constitutional arguments as if it were “a run-of-the-mill commercial dispute.” If the appeals court refuses to intervene, they argued, the case will proceed into the evidence-gathering phase, in which Mr. Trump will be forced to reveal details of his financial affairs.