Interpretation Act 1978

If an Act confers upon any authority power to make, grant or issue a statutory instrument, any instrument so made, granted or issued shall be read and construed subject to the Act under which it was made and so as not to exceed the power of that authority, to the intent that, where any such instrument would, but for this section, have been construed as being in excess of the power conferred upon that authority, it shall nevertheless be a valid instrument to the extent to which it is not in excess of that power.

It is presumed, unless the contrary is proved, that all conditions and steps required for the making, granting or issuing of a statutory instrument have been satisfied and carried out.