28Differing service liabilities of those called out
(1)Where a person—
(a)is in service in pursuance of a notice under section 14(1) above or in pursuance of a call-out notice under section 26(1) above specifying an enactment mentioned in section 26(1), and
(b)if he were not in service he would be liable to be called into service by a call-out notice under section 26(1) or, as the case may be, by such a call-out notice specifying a different enactment so mentioned,
the Secretary of State may direct that, on the date of the direction or a later date specified in the direction, that person shall be deemed to be called into service by a call-out notice under section 26(1) specifying such of those enactments applicable to him as is specified in the direction.
(2)Where a person is deemed in pursuance of subsection (1) above to be called into service by virtue of an enactment specified in a direction under that subsection, his service under any other enactment by virtue of which he was previously serving shall cease.
(3)The power to give a direction under this section includes power—
(a)to make provision for persons of such descriptions as are specified in the direction or in respect of an individual; and
(b)to make different provision for different circumstances.