25.—(1) The date, time and place of a hearing is to be appointed by the tribunal.
(2) The tribunal must give notice to the parties of the appointed date, time and place of the hearing.
(3) Subject to paragraph (4) notice of the hearing must be given not less than 21 days before the appointed date.
(4) In exceptional circumstances the tribunal may, without the agreement of the parties, give less than 21 days' notice of the appointed date, time and place of the hearing; but any such notice must be given as soon as practicable before the appointed date and the notice must specify what the exceptional circumstances are.