Principle of legality
18.7 The principle of legality provides protection to judicial review. When interpreting a statute, courts will presume that Parliament did not intend to restrict access to the courts, unless this intention was made unambiguously clear. For example, in Magrath v Goldsborough Mort & Co Ltd, Dixon J said:
The general rule is that statutes are not to be interpreted as depriving superior Courts of power to prevent an unauthorized assumption of jurisdiction unless an intention to do so appears clearly and unmistakably.
18.8 In Public Service Association (SA) v Federated Clerks’ Union, Dawson and Gaudron JJ said:
Privative clauses… are construed by reference to a presumption that the legislature does not intend to deprive the citizen of access to the courts, other than to the extent expressly stated or necessarily to be implied.
18.9 Dawson and Gaudron JJ went on to say:
Thus, a clause which is expressed only in general terms may be construed so as to preserve the ordinary jurisdiction of a superior court to grant relief by way of the prerogative writs of mandamus or prohibition in the case of jurisdictional error constituted by failure to exercise jurisdiction or by an act in excess of jurisdiction.
18.10 Hockey v Yelland also concerned a privative clause—specifically, a Queensland statute that provided that determinations by a medical board ‘shall be final and conclusive’ and the claimant ‘shall have no right to have any of those matters heard and determined by an Industrial Magistrate, or, by way of appeal or otherwise, by any Court or judicial tribunal whatsoever’. Gibbs CJ said that this provision did not ‘oust the jurisdiction of the Supreme Court to issue writs of certiorari’:
It is a well recognized principle that the subject’s right of recourse to the courts is not to be taken away except by clear words… The provision that the board’s determination shall be final and conclusive is not enough to exclude certiorari… The words of the further provision… are in my opinion quite inapt to take away from the Court its power to issue certiorari for error of law on the face of the record.
18.11 Where a statute purports to make it ‘unambiguously clear’ that Parliament intends to restrict access to the courts, the Constitution provides further protection. It provides for an ‘entrenched minimum provision of judicial review’, which cannot be removed by statute. Section 75(v) of the Constitution provides that the High Court shall have original jurisdiction in all matters ‘in which a writ of Mandamus or prohibition or an injunction is sought against an officer of the Commonwealth’. Gleeson CJ said that this provision ‘secures a basic element of the rule of law’:
The jurisdiction of the Court to require officers of the Commonwealth to act within the law cannot be taken away by Parliament. Within the limits of its legislative capacity, which are themselves set by the Constitution, Parliament may enact the law to which officers of the Commonwealth must conform. If the law imposes a duty, mandamus may issue to compel performance of that duty. If the law confers power or jurisdiction, prohibition may issue to prevent excess of power or jurisdiction. An injunction may issue to restrain unlawful behaviour. Parliament may create, and define, the duty, or the power, or the jurisdiction, and determine the content of the law to be obeyed. But it cannot deprive this Court of its constitutional jurisdiction to enforce the law so enacted.
18.12 In light of this constitutional jurisdiction, courts may construe privative clauses much more narrowly than the text of the provision suggests. So much more narrowly in fact, that such clauses may sometimes be largely or even entirely deprived of effect. The courts have justified such interpretive approaches by reference to the assumption that legislation should, as far as reasonably possible, be interpreted in a way that favours constitutional validity.
The principle of statutory interpretation now known as the ‘principle of legality’ is discussed more generally in Ch 1.
Momcilovic v The Queen (2011) 245 CLR 1, – (French CJ).
Magrath v Goldsbrough Mort & Co Ltd (1932) 47 CLR 121, 134.
Public Service Association (SA) v Federated Clerks’ Union of Australia (1991) 173 CLR 132, 160 (Dawson and Gaudron JJ). Quoted with approval in Plaintiff S157/2002 v Commonwealth (2003) 211 CLR 476, – (Gleeson CJ).
Public Service Association (SA) v Federated Clerks’ Union of Australia (1991) 173 CLR 132,  (Dawson and Gaudron JJ).
Workers’ Compensation Act 1916 (Qld) (repealed), quoted in Hockey v Yelland (1984) 157 CLR 124, 128 (Gibbs CJ).
Plaintiff S157/2002 v Commonwealth (2003) 211 CLR 476, .
Australian Constitution s 75(v).
Plaintiff S157/2002 v Commonwealth (2003) 211 CLR 476,  (Gleeson CJ).
See, eg, Plaintiff S157/2002 v Commonwealth (2003) 211 CLR 476. Section 474 of the Migration Act 1958 (Cth) purports to exclude challenging, appealing, reviewing, quashing or any calling into question a ‘privative clause decision’. It also purports to exclude prohibition, mandamus, injunction, declaration or certiorari as a remedy in any court. In Plaintiff S157/2002 the High Court unanimously rejected the literal interpretation, and held that the writs of mandamus and prohibition were available for decisions involving jurisdictional error.
The long history of authority to this effect was noted in Ibid  (Gaudron, McHugh, Gummow, Kirby and Hayne JJ). While this approach may lead the courts to interpret privative clauses in a manner that gives them very limited scope, alternative approaches may be more likely to require courts to find that a privative clause was invalid on constitutional grounds. Once this possibility is recognised, the value of interpretive approaches that enable some effect to be given to privative clauses can be understood.