This case is primarily one which was concerned with the procedural niceties of judicial review, laying out the principle that public law claims were to be dealt with exclusively by judicial review and private law claims were to be dealt with by Writ.Therefore this decision set a precedent in that it resulted in a locking of the remedies of injunction and the declaration that had entered the realm of the public domain by Common law, permanently into that domain. This does not appear to have been the original intent behind Lord Diplock’s judgment, for he has clearly stated that the Order 53 does not expressly provide that procedure by way of application for judicial review shall be the exclusive procedure available for obtaining remedy by injunction or declaration for infringement of rights under public law2. However, the fact that in this case, the invocation of a Writ was deemed to be an abuse of the process of the Court resulted in the subsequent position in law that only through the invoking of public law procedure could the remedies of declaration and injunction be obtained under judicial review.The orthodox approach to judicial review is based upon the absolute and indivisible sovereignty of the British Parliament3. The O’Reilly case also established that if the nature of the claim that is being made is that the public body acted ultra vires or outside the scope of its statutory powers, then this is a matter for judicial review. The ultra vires doctrine is based on the principle that all legal duties are created by Parliament4, therefore, the judicial function extends to the scope of controlling of the exercise of such statutory powers.