Sch 2 para 3
(1) An immigration officer or designated person may examine any person who is embarking or seeking to embark in the United Kingdom . . .for the purpose of determining whether he is a British citizen and, if he is not a British citizen, for the purpose of establishing— (a) his identity; (b) whether he entered the United Kingdom lawfully; (c) whether he has complied with any conditions of leave to enter or remain in the United Kingdom; (d) whether his return to the United Kingdom is prohibited or restricted. (1A) If a person is examined under sub-paragraph (1) (whether by an immigration officer or designated person), an immigration officer may require the person, by notice in writing, to submit to further examination by the immigration officer for a purpose specified in that sub-paragraph. (2) So long as any Order in Council is in force under section 3(7) of this Act, an immigration officer may examine any person who is embarking or seeking to embark in the United Kingdom . . . for the purpose of determining— (a) whether any of the provisions of the Order apply to him; and (b) whether, if so, any power conferred by the Order should be exercised in relation to him and in what way.