No person who has been an employee of the Department and attached to
the Washington office of any bureau,
board, division, or other agency thereof, shall be permitted to
practice, appear, or act as attorney, agent, or representative before
the Department or any branch or agent thereof, in connection with any
case or administrative proceeding pending before such bureau, board,
division, or other agency during the time of his employment with the
Department, unless he shall first obtain the written consent thereto of
the Secretary of Labor or his duly authorized representative.
