Judicial review, under which executive actions of the Government are subject to review, and possible invalidation, is used in New Zealand. Judicial review is carried out by a judge of the High Court of New Zealand. Legislative action is not justiciable in the High Court under New Zealand's Westminster constitutional arrangements; Parliament remains supreme in law. The Judicature Act 1908 and its amendments, especially the Judicature Amendment Act 1972, govern the process of judicial review.