No offence against the Act has been committed by the prosecutor company. Accordingly the question upon which the liability of the company to cancellation or suspension of its registration depends is whether it is unfit to continue to be registered or has acted in a manner whereby the proper performance of stevedoring operations has been interfered with. But the power of the board or its delegate to cancel or suspend registration does not depend upon the fulfilment of one or other of these conditions as a matter of objective truth or reality. It depends upon the satisfaction of the board or its delegate that one or other of the conditions does exist. If the board or its delegate is subjectively "satisfied" that the prosecutor company is either unfit to continue to be registered or has acted in a manner whereby the performance of stevedoring operations has been interfered with, then the power exists (assuming always the validity of the provisions) to cancel or suspend the company's registration no matter how erroneous in point of fact the opinion of the board or its delegate may be. But it does matter if the opinion is erroneous in point of law. That is to say the board or its delegate must understand correctly the test provided or prescribed by s. 23 (1) and actually apply it. It is only when the board or its delegate is satisfied of the existence of facts which do amount in point of law to what the section means by unfitness or by acting in a manner whereby the proper performance of stevedoring operations is interfered with that the board or its delegate reaches a position where one or other of them may lawfully exercise the authority which s. 23 (1) purports to bestow. The first point to observe is that it must always be open to the board or its delegate to investigate the question whether a case exists for the exercise of its powers. There can be nothing wrong or unlawful in the board or its delegate entering upon an inquiry into any of the matters described by the three paragraphs of s. 23 (1). It is therefore evident that no prohibition could go to restrain the holding of an inquiry directed to any one or more of those issues. There can be no foundation for a writ of prohibition unless and until it appears, whether from the course of the inquiry or from the preliminary statement of the matters to which the inquiry is directed, that there can be no basis for the exercise of the power conferred by s. 23 (1) or that an erroneous test of the liability of the employer to the cancellation or suspension of his registration will be applied or that some abuse of authority is likely. In any such case a writ of prohibition may lie but it must be a writ restraining the ordering of cancellation or suspension. If on the facts no basis could exist for exercising the power it would be a proper exercise of this Court's jurisdiction to award a writ of prohibition prohibiting unconditionally or peremptorily the cancellation or suspension threatened. For in the first place the board and the delegate are doubtless officers of the Commonwealth. At all events that has not been disputed. In the second place, although the power of the board is administrative, modern English authority has extended the writ to statutory bodies exercising quasi-judicial powers affecting the rights of private persons and the board comes fairly within the application of the remedy as now understood: cf. R. v. Electricity Commissioners; Ex parte London Electricity Joint Committee Co. (1920) Ltd. [1] ; R. v. Minister of Health; Ex parte Davis [2] ; Estate & Trust Agencies Ltd. v. Singapore Improvement Trust [3] ; R. v. Commonwealth Rent Controller; Ex parte National Mutual Life Association of Australasia Ltd. [4] ; R. v. City of Melbourne; Ex parte Whyte [5] . If the facts are not inconsistent with the existence of a basis for exercising the board's power of suspension or cancellation but there is a real threat to apply an erroneous test or to go outside the scope of the discretion and so abuse the power, more difficulty as to the remedy in prohibition may arise. But the tenor of the writ might perhaps be moulded to meet the situation and the board and its delegate prohibited quousque, e.g. until they were satisfied lawfully or until they abandoned the unlawful course or criterion: see per Willes J. in Mayor of London v. Cox [6] , and in White v. Steele [7] . Now it might be said that until an order for cancellation or suspension of the registration of an employer has been actually made the Court ought not to consider whether the basis for making such an order is so wanting that the power has not arisen or whether to exercise the power means the application of an erroneous test or some other abuse, and that accordingly the Court should withhold the writ until the result of the inquiry is known. There are two observations to make upon such a view of the matter. The first is that it must be borne in mind that, subject to certain limitations not here material, while prohibition is not a writ of course, it is a writ which goes as of right when the prosecutor is directly affected by the course pursued by a tribunal to which the writ lies and the prosecutor shows satisfactorily that the tribunal is about to act to his detriment in excess of its authority. The second observation is that the existence of s. 52 in the Act supplies a strong reason for the prosecutor seeking the protection of the writ before the board or its delegate orders cancellation or suspension when it or he threatens to make such an order although the requisite basis for the exercise of the power is absent or the grounds upon which it is threatened are legally misconceived, and extraneous to the board's authority. Section 52 provides that: "An order or direction of the Board shall not be challenged, appealed against, reviewed, quashed or called in question, or be subject to prohibition, mandamus or injunction, in any court on any account whatever". Similar provisions have been considered in this Court in R. v. Hickman; Ex parte Fox [1] ; R. v. Murray; Ex parte Proctor [2] ; R. v. Metal Trades Employers' Association; Ex parte Amalgamated Engineering Union, Australian Section [3] . It is unnecessary now to discuss the extent of the operation or of the validity of s. 52, but whatever view may be taken on that question the section shows not only that the legislature desired that the authority of the board should not be impugned after it had made an order, but also that to defer the grant of the remedy until that event, where otherwise the prosecutor is entitled to a writ, may and perhaps must operate to the prejudice of the prosecutor. At common law a prosecutor is expected to apply at the earliest stage at which his right to a writ arises, but he is not entitled to the remedy quia timet, that is before the tribunal is invoked or assumes a jurisdiction or authority over the matter and, where the complaint is that an order may be made in excess of power or notwithstanding that the power has not attached, the prosecutor must show a real likelihood or danger of such an order being made.