13. British subjects whose citizenship has not been ascertained at the commencement of this Act.-
(1)A person who was it British subject immediately before the date of commencement of this'Act and is at that date potentially a citizen of any country mentioned in sub-section (3) of section 1 of this Act, but is not at that date a citizen of the United Kingdom and Colonies or of any country mentioned in that sub-section or Eire, shall as from that date remain a British subject without citizenship until he becomes a citizen of the United Kingdom and Colonies, a citizen of any country mentioned in sub-section (3) of section I of this Act, a citizen of Eire or an alien; and the provisions of the Third Schedule to this Act shall have effect in relation to a person who remains a British subject without citizenship by virtue of this section.(2)A person remaining a British subject without citizenship as aforesaid shall become a citizen of the United Kingdom and Colonies on the day on which a citizenship law has taken effect in each of the countries mentioned in sub-section (3) of section 1 of this Act of which he is potentially a citizen, unless he then becomes or has previously become a citizen of any country mentioned in sub-section (3) of section 1 of this Act, or has previously become a citizen of the United Kingdom and Colonies, a citizen of Eire or an alien.(3)A male person who becomes a citizen of the United Kingdom and Colonies by virtue of the last foregoing sub-section shall be deemed for the purposes of the proviso to sub-section (1) of section 5 of this Act to be a citizen thereof by descent only.
