Deputy Attorney General Paul McNulty said Monday he will resign, becoming the highest-ranking Bush administration casualty in the furor over the firing of U.S. Attorneys.

McNulty, who has served 18 months as the Justice Department’s second-in-command, announced his plans at a closed-door meeting of U.S. Attorneys in San Antonio. He told them he would remain at the department until late summer or until the Senate approves a successor, aides said.