(1)Subject to subsection (3), a person shall be entitled, on an application for his registration as a British citizen, to be registered as such a citizen if immediately before commencement he would (had he applied for it) have been entitled under section 1(1) of the [1964 c. 22.] British Nationality Act 1964 (resumption of citizenship) to be registered as a citizen of the United Kingdom and Colonies by virtue of having an appropriate qualifying connection with the United Kingdom or, if a woman, by virtue of having been married before commencement to a person who has, or would if living have, such a connection.
(2)On an application for his registration as a British citizen made by a person of full capacity who had before commencement ceased to be a citizen of the United Kingdom and Colonies as a result of a declaration of renunciation, the Secretary of State may, if he thinks fit, cause that person to be registered as a British citizen if that person—
(a)has an appropriate qualifying connection with the United Kingdom; or
(b)if a woman, has been married to a person who has, or would if living have, such a connection.
(3)A person shall not be entitled to registration under subsection (1) on more than one occasion.
(4)For the purposes of this section a person shall be taken to have an appropriate qualifying connection with the United Kingdom if he, his father or his father's father—
(a)was born in the United Kingdom ; or
(b)is or was a person naturalised in the United Kingdom; or
(c)was registered as a citizen of the United Kingdom and Colonies in the United Kingdom or in a country which at the time was mentioned in section 1(3) of the 1948 Act.