4(1)The Secretary of State shall appoint—
(a)a Commissioner as Chairman, and
(b)one or more Commissioners as deputy Chairman.
(2)The Chairman shall—
(a)preside over meetings of the Commission,
(b)perform such functions as may be specified in the terms of his appointment, and
(c)perform such other functions as may be assigned to him by the Commission.
(3)A deputy Chairman—
(a)may act for the Chairman when he is unavailable, and
(b)shall perform—
(i)such functions as may be specified in the terms of his appointment, and
(ii)such other functions as the Chairman may delegate or assign to him.
(4)The Chairman or a deputy Chairman—
(a)shall vacate office if he ceases to be a Commissioner,
(b)may resign by notice in writing to the Secretary of State, and
(c)otherwise, shall hold and vacate office in accordance with the terms of his appointment (and may be reappointed).
(5)If the Chairman resigns he shall cease to be a Commissioner (but he may be reappointed as a Commissioner).
(6)The chief executive may not be appointed Chairman or deputy Chairman.