23.—(1) The tribunal may alter the time and place of the hearing–
(a)where both the appellant and the Secretary of State agree, or
(b)in exceptional circumstances, provided that the altered date of the hearing is not earlier than the original date.
(2) Where the tribunal alters the time or place of the hearing under paragraph (1)(b), it must without delay inform the appellant and the Secretary of State in writing of the alteration and the reasons for it.