12.—(1) An appellant may amend a notice of grounds of appeal or supplementary grounds of appeal at any time before the preliminary hearing and shall forthwith notify the Bank and the secretary in writing of the amendment.
(2) An appellant may amend a notice of grounds of appeal or supplementary grounds of appeal in the course of the preliminary hearing with the leave of the chairman or at any time thereafter with the leave of the Tribunal.
(3) The chairman or the Tribunal shall not give such leave unless he or it has afforded the Bank an opportunity of making representations on the proposed amendment.
(4) Leave may be granted on such terms (if any), including terms as to expenses, as the chairman or the Tribunal (as the case may be) thinks fit.
(5) Where a notice of grounds of appeal is amended the appellant shall forthwith notify any person to whom a copy of the notice was sent pursuant to regulation 8(2) and where a notice of supplementary grounds of appeal is amended the chairman shall consider whether any matters contained therein should be disclosed to any other person and may direct accordingly.