"(1) For the purposes of this Act a British citizen is a British citizen 'by descent' if and only if -- (i) was a citizen of the United Kingdom and Colonies by virtue of section 5 of the 1948 Act (citizenship by descent);"
"(1) Subject to the provisions of this section, a person born after the commencement of this Act shall be a citizen of the United Kingdom and Colonies by descent if his father is a citizen of the United Kingdom and Colonies at the time of the birth:"
"(2) Except as provided by section 3 of this Act, any person who immediately before the appointed day is a citizen of the United Kingdom and Colonies shall on that day cease to be such a citizen if he becomes on that day a citizen of Mauritius."
"(1) Every person who, having been born in Mauritius, is on11th March 1968 a citizen of the United Kingdom and Colonies shall become a citizen of Mauritius on12th March 1968 ."
"4. Nigeria became independent on1st October 1960 . Bysection 2(2) of the Nigeria Independence Act 1960 those who had been citizens of the United Kingdom and Colonies immediately before that date ceased to have that status if under the law of Nigeria they became citizens of Nigeria on that date and they themselves or their fathers or grandfathers had been born in the territories comprised in Nigeria. Under the Constitution of Nigeria all those who had been born in the former colony and were citizens of the United Kingdom and Colonies on30th September 1960 became citizens of Nigeria on1st October 1960 . The combined effect of these provisions was that the respondent's father ceased to be a citizen of the United Kingdom and Colonies on1st October 1960 ."
"15. As I have already mentioned, the respondent's father became a citizen of the United Kingdom and Colonies on the coming into force of theBritish Nationality Act 1948 , but he had been born in Nigeria and lost his status as a citizen of the United Kingdom and Colonies on1st October 1960 when Nigeria became independent. When the respondent was born in 1975, therefore, his father was no longer a citizen of the United Kingdom and Colonies and was unable to pass that status on to him. As a result the respondent could not acquire British citizenship by descent from his father under section 11 of the 1981 Act (see paragraph 8 above)."