4(1)The Commission shall at its annual meeting in each year elect one of the Commissioners to be chairman and, unless the chairman resigns that office or otherwise ceases to be a member of the Commission, the chairman shall continue in office until a successor is elected.
(2)The Commission shall at each annual meeting appoint one of the Commissioners to be vice-chairman and, unless the vice-chairman resigns that office or ceases to be a member of the Commission, the vice-chairman shall continue in office until immediately after the election of the chairman at the next annual meeting.
(3)On a casual vacancy occurring in the office of chairman or vice-chairman of the Commission—
(a)the vacancy shall be filled by the appointment by the Commission of one of their number at a meeting held as soon as practicable after the vacancy occurs and,
(b)where the office vacant is that of chairman, the meeting may be convened by the secretary or such other officer as shall be appointed for the purpose by the Commission.
(4)A person appointed under this paragraph to fill a vacancy shall hold office until the date of the next annual meeting.