2.—(1) Subject to sub-paragraph (2), where a member is unwilling or unable to perform his functions another person may be appointed in the same manner to be a member in his place.
(2) Where the person who is unwilling or unable to perform his functions is—
(a)the chief officer of the Authority, another officer member of the Authority shall be appointed to act in his place;
(b)a professional member appointed in accordance with paragraph 2(d) or (e) of Schedule 1, another professional member shall be appointed to act in his place.