CCSU

Judicial review of non-statutory executive powers can give rise to a tension between competing principles. On the one hand, the rule of law requires the courts to review the legality of executive action. On the other hand, the separation of powers precludes the Court from trespassing into matters entrusted or committed to other branches of government. The fundamental role of the court in judicial review proceedings is to identify and enforce limits on executive power, whether derived from statute, prerogative or the common law. In this way, 'judicial review is neither more nor less than the enforcement of the rule of law over executive action'.At Commonwealth level, the entrenched original jurisdiction of the High Court under s 75 of the Constitution 'is a means of assuring to all people affected that officers of the Commonwealth obey the law and neither exceed nor neglect any jurisdiction which the law confers on them'For this reason, it is necessary to maintain the role of courts in supervising the exercise of non-statutory powers by the executive.
However, the scope of review in any particular case must take account of the nature and subject matter of the power relied upon by the executive, and the context in which it is exercised. Some aspects of some non-statutory powers may be non-justiciable, and beyond the proper role of the courts. Ultimately, this is a reflection or application of principles relating to separation of powers, in that the courts' role is confined 'to the exercise of judicial power in relation to issues not properly assignable to other branches of government under the separation of powers and otherwise within the institutional competence of the courts'