(1)A man of the Army Reserve may, with the consent of the prescribed authority, enlist in the Territorial Army and shall on so enlisting cease to be a man of the Army Reserve.
(2)If a man who has enlisted into the Territorial Army in pursuance of subsection (1) above—
(a)ceases to be a member of that reserve before the date on which his term of service in the Army Reserve would have expired if he had not so enlisted, then,
(b)he shall, unless the prescribed authority otherwise directs (and that power of direction includes power to make different provision for different circumstances), again be a man of the Army Reserve by virtue of this subsection for the residue of that term, without prejudice to the operation of any enactment under which that term may be extended.