18. (1) The Minister may, by instrument, appoint a person to be the deputy of a member.
(2) A person shall not be appointed under subsection (1) unless the person is eligible for appointment as a member.
(3) In the absence of a member, the member's deputy may act in the office of the member.
(4) Anything done by or in relation to a person purporting to act under this section is not invalid on the ground that—
(a) the occasion for the person's appointment had not arisen;
(b) there is a defect or irregularity in connection with the person's appointment;
(c) the person's appointment had ceased to have effect; or
(d) the occasion for the person to act had not arisen or had ceased.