any account whatever", an issue that had not been considered by the High Court in R v Commonwealth Court of Conciliation and Arbitration; Ex parte BHP. The majority, Griffith CJ, Barton & O'Connor JJ held that prohibition was an exercise of the High Court's original jurisdiction. and that s 31 of the Conciliation and Arbitration Act was not effective to deny the High Court's jurisdiction to order prohibition. Isaacs J dissented on this point, holding that prohibition was an exercise of the High Court's appellate jurisdiction. The High Court was required to consider the operation of the power to grant prohibition, rather than whether prohibition was the appropriate remedy. In this way the High Court granted prohibition where certiorari would have been an appropriate remedy and extended the scope of prohibition beyond generally accepted limits. Compulsory arbitration The boot manufacturers argued that arbitration required the voluntary submission to the tribunal and a choice by the disputants as to how the tribunal was constituted and that the compulsory arbitration provided for by the Conciliation and Arbitration Act, was unconstitutional. This argument was rejected by each of the judges. Common rule award The Conciliation and Arbitration Act provided at s 38(f) that the Arbitration Court could declare an award to be a common rule of any industry. The other constitutional argument was that the Australian parliament had no power to provide for common rule awards. There were two impediments to this argument (1) the award had not at that time been declared to be a common rule award and (2) The boot manufacturers who applied to the High Court were all parties to the dispute and thus would be bound by the Award regardless. As Higgins had noted, the High Court will not answer a constitutional question unless it is necessary. The State of Victoria had intervened in the case to protect the public of that State from the operation of what it said was an invalid federal law. The argument was that the common rule provisions were invalid and could not be severed from the balance of the Act, such that the entire Act was invalid. Barton O'Connor and Isaacs JJ declined to express a view on whether the common rule provisions were invalid, holding that on the assumption that the common rule provisions were unconstitutional, they were severable from the Act. That is the Award was valid, even if the