‘…if there was an express power to revoke’ in either provision ‘there would be no need to imply a power to do so or to rely on’ the 1978 Act ‘at all’
‘(1) Where an Act passed after the commencement of this Act confers a power or imposes a duty, then, unless the contrary intention appears, the power may be exercised and the duty shall be performed from time to time as occasion requires. (2) Where an Act passed after the commencement of this Act confers a power or imposes a duty on the holder of an office, as such, then, unless the contrary intention appears, the power may be exercised and the duty shall be performed by the holder for the time being of the office. (3) Where an Act passed after the commencement of this Act confers a power to make any rules, regulations, or byelaws, the power shall, unless the contrary intention appears, be construed as including a power, exerciseable in the like manner and subject to the like consent and conditions, if any, to rescind, revoke, amend, or vary the rules, regulations, or byelaws.’
‘Where an Act confers a power or imposes a duty it is implied, unless the contrary intention appears, that the power may be exercised, or the duty is to performed, from time to time as the occasion requires.’
‘Where an Act confers a power or imposes a duty on the holder of an office as such, it is implied, unless the contrary intention appears, that the power may be exercised, or the duty is to be performed, by the holder for the time being of the office’
‘Where an Act confers power to make- (a) rules, regulations or byelaws; or (b) Orders in Council, orders or other subordinate legislation to be made by statutory instrument, it implies, unless the contrary intention appears, a power, exercisable in the same manner and subject to the same conditions or limitations, to revoke, amend or re-enact any instrument made under the power.’