(1)Subject to the provisions of this Part of this Act, where directions are given under this Act for a person's removal from the United Kingdom either—
(a)on the ground that he is an illegal entrant or on the ground specifically that he has entered the United Kingdom in breach of a deportation order; or
(b)under the special powers conferred by Schedule 2 to this Act in relation to members of the crew of a ship or aircraft or persons coming to the United Kingdom to join a ship or aircraft as a member of the crew;
then he may appeal to an adjudicator against those directions on the ground that in the facts of his case there was in law no power to give them on the ground on which they were given.
(2)A person shall not be entitled to appeal under this section so long as he is in the United Kingdom, unless he is appealing against directions given by virtue of a deportation order (whether on the ground specifically that he has returned in breach of that order or on the ground that he is an illegal entrant) and is appealing on the ground that he is not the person named in that order.
(3)Where a person appeals under this section against directions given by virtue of a deportation order, he shall not be allowed to dispute the original validity of that order.
(4)An appeal under this section against directions given as mentioned in subsection (1)(b) shall be dismissed by the adjudicator, notwithstanding that the ground of appeal may be made out, if he is satisfied that there was power to give the like directions on the ground that the appellant was an illegal entrant.