Interpretation Act 1987 No 15
31 Acts and instruments to be construed so as not to exceed the legislative power of Parliament
(1) An Act or instrument shall be construed as operating to the full extent of, but so as not to exceed, the legislative power of Parliament.(2) If any provision of an Act or instrument, or the application of any such provision to any person, subject-matter or circumstance, would, but for this section, be construed as being in excess of the legislative power of Parliament:(a) it shall be a valid provision to the extent to which it is not in excess of that power, and(b) the remainder of the Act or instrument, and the application of the provision to other persons, subject-matters or circumstances, shall not be affected.(3) This section applies to an Act or instrument in addition to, and without limiting the effect of, any provision of the Act or instrument.