[L]egal advice sought from Mark Robinson SC concluded that “the dispensations contravene relevant provisions of all three legislative instruments and subverts the rightful and lawful role of parliament”.
Here’s what the Curfew Act says:
20 Dispensations in exceptional circumstances
(1) The Minister may grant a dispensation authorising an aircraft to take off from, or land at, Sydney Airport in circumstances that would otherwise contravene section 7, 10 or 11 if the Minister is satisfied that there are exceptional circumstances justifying the take‑ off or landing.
(2) A dispensation may be granted subject to conditions including, for example, conditions relating to when the take‑off or landing must occur and the runway to be used.
(3) In granting dispensations, the Minister must have regard to guidelines made under subsection (5).
(4) A dispensation need not be in writing, but a written record of each dispensation and the reasons for granting it must be made and must be tabled in each House of the Parliament within 5 sitting days of that House after the dispensation is granted.
(5) The Minister must, by legislative instrument, make guidelines about the granting of dispensations under this section including, in particular:
(a) what constitutes exceptional circumstances; and
(b) the conditions to which dispensations should be subject.
(7) The consultation procedures set out in the Schedule apply if the Minister proposes to make guidelines under subsection (5).
The Guidelines are
here.