Article 47 Summoning of witnesses
(1)
An adjudicator or the Tribunal may, by issuing a summons (“a witness summons”), require any person in the United Kingdom—
(a)
to attend as a witness at the hearing of an appeal; and
(b)
subject to rule 48(2), at the hearing to answer any questions or produce any documents in his custody or under his control which relate to any matter in issue in the appeal.
(2)
A person is not required to attend a hearing in obedience to a witness summons unless—
(a)
the summons is served on him; and
(b)
the necessary expenses of his attendance are paid or tendered to him.
(3)
If a witness summons is issued at the request of a party, that party must pay or tender the expenses referred to in paragraph (2)(b).