Summoning of witnesses and administration of oaths
15.—(1) A chairman, or in the case of an appeal tribunal which has only one member, that member, may by summons, or in Scotland, by citation, require any person in Great Britain to attend as a witness at a hearing of an appeal, an application for a direction or penalty proceedings, at such time and place as shall be specified in the summons or citation and, subject to paragraph (2), at the hearing to answer any question or produce any documents in his custody or under his control which relate to any matter in question in that appeal, application or those proceedings but—
(a)no person shall be required to attend in obedience to such summons or citation unless he has been given at least 14 days' notice of the hearing or, if less than 14 days' notice is given, he has informed the tribunal that the notice given is sufficient; and
(b)no person shall be required to attend and give evidence or to produce any document in obedience to such summons or citation unless the necessary expenses of attendance are paid or tendered to him.
(2) No person shall be compelled to give any evidence or produce any document or other material that he could not be compelled to give or produce on a trial of an action in a court of law in that part of Great Britain where the hearing takes place.
(3) In exercising the powers conferred by this regulation, the chairman, or in the case of an appeal tribunal which has only one member, that member, shall take into account the need to protect any matter that relates to intimate personal or financial circumstances, is commercially sensitive, consists of information communicated or obtained in confidence or concerns national security.
(4) Every summons or citation issued under this regulation shall contain a statement to the effect that the person in question may apply in writing to a chairman to vary or set aside the summons or citation.
(5) A chairman, or in the case of an appeal tribunal which has only one member, that member, may require any witness, including a witness summoned under the powers conferred by this regulation, to give evidence on oath or affirmation and for that purpose there may be administered an oath or affirmation in due form.