53. A person who for the time being—

(a) holds judicial office outside the State,

(b) holds the office of judge of the International Court of Justice established under the Charter of the United Nations, or

(c) holds the office of judge of an international tribunal (within the meaning of section 2 of the International War Crimes Tribunals Act 1998),

shall vacate the office concerned before the President appoints the person to a judicial office in the State.