25. Power to appoint to substantive office not vacant

Notwithstanding the provisions of any written law constituting an office, when the substantive holder of such office is on leave of absence pending relinquishment of his office, it shall be lawful for another person to be appointed substantively to the same office; and, upon any such appointment, all rights, powers, functions and duties of the office shall vest in the person so appointed to the exclusion of the holder of such office on leave of absence pending relinquishment of office, but without prejudice to the provisions of section 19(2), or to any provision enabling an acting appointment to be made, or enabling a person other than the holder of an office to exercise and discharge temporarily the powers and duties of that office or some of them.