The presumption of constitutionality has been frequently invoked in recent judgments of Murphy J in the High Court. The article examines the use of the presumption in the United States and Canada. It then considers the way in which the presumption has been applied in Australia and the justification given for it. It is suggested that although the presumption does not have a clearly recognised place in Australian constitutional theory, the presumption is important and it should be given much greater prominence. For this to happen will require changes in judicial attitude. It also requires Parliament to reassert its role in the determination of constitutional questions.

The notion of the relevant market, together with the process for identifying it, is a construct used in competition law in order to determine whether competition exists between two or more producers for the purposes of Part IV of the Trade Practices Act 1974 (Cth).

This legislation confers upon the courts and the Trade Practices Tribunal the duty to decide whether certain courses of conduct have the purpose, or have (or are likely to have) the effect, of substantially lessening competition in a market. The market delineation process provides the first in a set of stepping-stones which enable the courts to discharge this task in the principled and certain manner that is required by the doctrine of the rule of law. The procedures comprised within it enable the court (or other trier of fact) to organise complex fact situations and classify them in such a way as to enable competition policy, as embodied in legislation such as the Trade Practices Act, to be intelligently applied. It permits a degree of quantitative evaluation which in practice would not be possible if the lessening-of-competition issue were attacked directly.

Can the formal amendment process embodied in s 128 of the Commonwealth Constitution be utilised to patriate the Constitution, to make Australia a republic, to establish a Bill of Rights, to abolish State Constitutions or Parliaments and to alter s 128 itself or provide a completely new amendment procedure? What is the ambit of s 128? This article considers the history, scope and interpretation of s 128.