At any time when—

1. the office of a Judge of the Federal Constitutional Court is vacant; or
2. a Judge of the Federal Constitutional Court is absent or is unable to perform the functions of his office due to any other cause,

the President may, in the manner provided in clause (1) of Article 175A, appoint a Judge of the Supreme Court or a High Court who is qualified for appointment as a Judge of the Federal Constitutional Court to act temporarily as a Judge of the Federal Constitutional Court.
Explanation. In this clause, Judge of the Supreme Court or a High Court includes a person who has retired as a Judge of the Supreme Court or a High Court.

1. An appointment under this Article shall continue in force until it is revoked by the President.