The High Court's decision has left the scope of unreasonableness as a basis for challenging subordinate legislation somewhat unclear

Can subordinate legislation be challenged on the basis it is unreasonable? In Attorney-General (SA) v Corporation of the City of Adelaide [2013] HCA 3, the High Court was asked to strike down subordinate legislation on this ground.

The by-law and the preacher

The legislation in question was a by-law made by the Adelaide City Council which had the effect of prohibiting preaching, canvassing or distributing materials on a road without the permission of the Council. The by-law was challenged by a group called "Street Church" and one of its members, Mr Corneloup, who described himself as an "expositor of the Gospel". Mr Corneloup was convicted of preaching on a road in the Council area without permission and fined $250.

Mr Corneloup argued that the by-law was an unreasonable exercise of the by-law making power or that it was not "a reasonably proportionate or proportionate exercise of the power". He also argued that the by-law offended the implied freedom of political communication. A majority of the High Court (Chief Justice French, Justices Hayne, Crennan, Kiefel and Bell; Justice Heydon dissenting) held that the by-law was valid.

The test of unreasonableness

Chief Justice French

Chief Justice French held that there is a high threshold test of unreasonableness of the kind which would invalidate a subordinate law. He referred to early authorities and noted that for a finding of unreasonableness requires something "fantastic and capricious" or involving oppressive or gratuitous interference with rights as could find "no justification in the minds of reasonable men". Against the background of this high threshold, he found the by-law:

"provided a rational mechanism for the regulation by proscription, absent permission, of conduct on roads which involves unsolicited communication to members of the public. They were not, on their face, capricious or oppressive. Nor did they represent a gratuitous interference with the rights of those affected by them. They provided a mechanism for protecting members of the public from gratuitous interference with their freedom to choose whether and, if so, when and where they would be the subject of proselytising communications."

Justice Hayne

Justice Hayne took a narrower view of unreasonableness in the review of subordinate legislation. His Honour's decision in relation to unreasonableness focused on the "legal and practical of the by-law to determine whether it has a sufficient connection to the by-law making power".

He held that "the question to be asked and answered is not whether the by-law is a reasonable or proportionate response to the mischief to which it is directed but whether, in its legal and practical operation, the by-law is authorised by the relevant by-law making power."

Justices Crennan and Kiefel

Justices Crennan and Kiefel (with Justice Bell agreeing) equated reasonableness with proportionality. They held that "[i]f the means employed go further than is reasonably necessary to achieve the legislative object, they will be disproportionate and invalid for that reason." In the event, Justices Crennan and Kiefel held that the by-law was a proportionate use of the by-law making power.

Different views leading to the same result

Justices Crennan's and Kiefel's merging of reasonableness and proportionality was at odds with the views of the Chief Justice, who held that proportionality is not a standalone ground of review in relation to delegated legislation. Rather, if there is a power to make delegated legislation for a particular purpose, proportionality is a useful analytical tool to examine whether the delegated legislation fits within the purposive power to make it.

However, the Chief Justice warned that this test is also a high bar, finding that the authorities make "it clear that a reviewing court is not entitled to substitute its own view of what would be a reasonable law for that of the legislature or a body exercising delegated legislative power." Mr Corneloup argued that the by-law was not reasonably proportionate because it was gravely oppressive, was fundamentally directed towards banning most forms of public communication or so widely drawn so as to capture matters not reasonably of concern to a local government authority. Chief Justice French disagreed, holding that it served legitimate ends and were reasonably appropriated and adapted as exercises of the by-law making power.

The majority also dismissed the challenge to the by-law on the basis that it offended the implied freedom of political communication. Although all judges in the majority held that the law did limit freedom of political communication, they found that it was reasonably appropriate and adapted to serve a legitimate end and was consistent with the Constitutionally-prescribed system of representative and responsible government.

When can unreasonableness be a basis for challenging subordinate legislation?

The reasoning of each of the judges in City of Adelaide does leave some uncertainty about the scope of unreasonableness as a basis for challenging subordinate legislation. The scope of review remains, in many respects, unclear.

Chief Justice French and Justice Hayne developed a limited scope for review for unreasonableness. However, the other members of the majority (Justices Crennan and Kiefel with Justice Bell agreeing) proposed a potentially broader scope of review relying on the concept of proportionality.

City of Adelaide was decided by six members of the High Court (Justice Gageler had not yet been appointed) and it may be that the High Court will clarify further the judicial thinking in relation to unreasonableness as a ground of invalidity with an expanded bench if the opportunity presents itself.