If the participation of any employee in any phase of any proceeding before the Board, including the investigation of unfair labor practice charges and representation petitions and the participation in hearings and representation elections, is deemed necessary by the Board, the General Counsel, any Administrative Law Judge, Regional Director, Hearing Officer, or other agent of the Board designated by the Board, such employee shall be granted official time for such participation, including necessary travel time, as occurs during the employee's regular work hours and when the employee would otherwise be in a work or paid leave status. In addition, necessary transportation and per diem expenses shall be paid by the Department.