The Commonwealth of Australia & Anor v Commissioner Bret Walker SC & Anor

The Commonwealth of Australia and the Murray-Darling Basin Authority (the plaintiffs) brought proceedings against Commissioner Bret Walker SC and the State of South Australia. The dispute concerned the interpretation of certain provisions of the Royal Commissions Act and constitutional questions arising from the operation of the Murray-Darling Basin Plan. The matter came before the High Court of Australia for directions regarding its hearing.

The primary legal issues before the Court were the construction of sections 10 and 11 of the Royal Commissions Act, specifically whether these provisions bind the Executive Government, including the executives of other polities, and a constitutional argument based on the principles in *Cigamatic Pty Ltd v. Federal Commissioner of Taxation* and *Henderson v. The Queen*. The Court also considered the procedural aspects of the case, including the estimated length of the hearing, the timetable for pleadings and the filing of submissions, and the role of interveners.

The Court, in its reasoning, acknowledged the urgency of the matter and the desire to accommodate it within the September sittings, though noting it would be challenging. The parties indicated that the core of the dispute involved statutory construction and a constitutional argument that would arise if the statutory construction argument failed. It was anticipated that there would be no significant factual dispute between the Commonwealth and South Australia, allowing for the matter to proceed as a special case. The Court proposed a mention on 30 July 2018 to ensure the matter was ready for referral to the Full Court, with a view to hearing it during the next available sitting, estimated to take two days. The Court made directions in accordance with the minutes of proposed orders, with amendments to reflect the proposed mention date and procedural arrangements for interveners.