The quorum of the Commission and the arrangements relating to its meetings shall, subject to any directions given by the Secretary of State, be such as the Commission may determine.

The quorum of any committee set up under paragraph 3 above and the arrangements relating to its meetings, so far as not provided for by the arrangements made for setting up the committee, shall be such as the committee may determine.

The validity of any proceedings of the Commission or of such a committee shall not be affected by any vacancy among its members or by any defect in the appointment of any of its members.