5.—(1) This regulation applies to a relevant authority which is—
(a)a county council or county borough council; or
(b)a joint planning board(1).
(2) The number of members appointed to a committee in accordance with regulation 4 must not exceed half of the total number of members of the relevant authority, rounded up to the nearest whole number.
A joint planning board may be constituted for an area in Wales by an order under section 2(1B) of the 1990 Act.