126.—(1) No person shall be registered as a citizen of Singapore under Article 123 until he has taken the Oath of Renunciation, Allegiance and Loyalty in the form set out in the Second Schedule.
(2) Except with the approval of the Government, no person who has renounced or has been deprived of citizenship of Singapore under this Constitution or the Singapore Citizenship Ordinance 1957 (Ord. 35 of 1957) shall be registered as a citizen of Singapore under the provisions of this Constitution.
(3) Any person who becomes a citizen of Singapore by registration under section 13 of the Singapore Citizenship Ordinance 1957 or Article 124 shall cease to be a citizen of Singapore on attaining the age of 22 years unless within 12 months after he attains the age of 21 years he takes the Oath of Renunciation, Allegiance and Loyalty in the form set out in the Second Schedule.