“The ratio decidendi of a case is any rule of law expressly or impliedly treated by the judge as a necessary step in reaching his conclusion, having regard to the line of reasoning adopted by him …”
‘First, in their criminal jurisdiction, what magistrates' have jurisdiction to try summarily is an information, and what is required to give them that jurisdiction is that an information has been laid before them.’ “At page 344C Lord Roskill said: ‘. . .it is the laying of an information . . . which is the foundation of the magistrates' court's jurisdiction to try an information to summarily . . .’
"The power to stop a prosecution arises only when it is an abuse of the process of the court. It may be an abuse of process if either (a) the prosecution have manipulated or misused the process of the court so as to deprive the defendant of a protection provided by the law or to take unfair advantage of a technicality, or (b) on the balance of probability the defendant has been, or will be, prejudiced in the preparation or conduct of his defence by delay on the part of the prosecution which is unjustifiable . . . The ultimate objective of this discretionary power is to ensure that there should be a fair trial according to law, which involves fairness to both the defendant and the prosecution." “There have, however, also been cases in which although the fairness of the trial itself was not in question the courts have regarded it as so unfair to try the accused for the offence that it amounted to an abuse of process. In Chu Piu-wing v. Attorney-General [1984] H.K.L.R. 411 the Hong Kong Court of Appeal allowed an appeal against a conviction for contempt of court for refusing to obey a subpoena ad testificandum on the ground that the witness had been assured by the Independent Commission Against Corruption that he would not be required to give evidence, McMulfin V.-P. said, at pp. 417-418: "there is a clear public interest to be observed in holding officials of the state to promises made by them in full understanding of what is entailed by the bargain." “And in a recent decision of the Divisional Court in Reg. v. Croydon Justices, Ex parte Dean [1993] Q.B. 769, the committal of the accused on a charge of doing acts to impede the apprehension of another contrary tosection 4(1) of the Criminal Law Act 1967 was quashed on the ground that he had been assured by the police that he would not be prosecuted for any offence connected with their murder investigation and in the circumstances it was an abuse of process to prosecute him in breach of that promise. “Your Lordships are now invited to extend the concept of abuse of process a stage further. In the present case there is no suggestion that the appellant cannot have a fair trial, nor could it be suggested that it would have been unfair to try him if he had been returned to this country through extradition procedures. If the court is to have the power to interfere with the prosecution in the present circumstances it must be because the judiciary accept a responsibility for the maintenance of the rule of law that embraces a willingness to oversee executive action and to refuse to countenance behaviour that threatens either basic human rights or the rule of law. “My Lords, I have no doubt that the judiciary should accept this responsibility in the field of criminal law.” "