Failure to comply with certain directions
17. If any directions given to a party under this Part are not complied with by that party, the Tribunal may, before or at the hearing, dismiss the whole or part of the appeal or, as the case may be, strike out the whole or part of the reply and, where appropriate, direct that the Authority shall be debarred from contesting the appeal altogether:
Provided that a Tribunal shall not so dismiss or strike out or give such a direction unless it has sent notice to the party who has not complied with the direction giving him an opportunity to show cause why it should not do so.