Immigration Act 1971

9(1)A person registered under any of the three last foregoing sections or under section 5A of this Act shall, on taking an oath of allegiance in accordance with subsection (2) below if so required by that subsection, be a citizen of the United Kingdom and Colonies by registration as from the date on which he is registered.

(2)A person of full age and capacity shall on registration as mentioned in subsection (1) above, if not already a citizen of a country of which Her Majesty is Queen nor a British subject by virtue of section 1 of the [1965 c. 34.] British Nationality Act 1965, take an oath of allegiance in the form specified in the First Schedule to this Act.