"(2) Subject to subsection (3) below, proceedings for an offence under section 1 above may be brought within a period of six months from the date on which evidence sufficient in the opinion of the prosecutor to warrant the proceedings came to his knowledge. (3) No such proceedings shall be brought by virtue of this section more than three years after the commission of the offence. (4) For the purposes of this section, a certificate signed by or on behalf of the prosecutor and stating the date on which evidence sufficient in his opinion to warrant the proceedings came to his knowledge shall be conclusive evidence of that fact. (5) A certificate stating that matter and purporting to be so signed shall be deemed to be so signed unless the contrary is proved."
".... that the proceedings have been brought within a period of six months from the date on which evidence sufficient in the opinion of the prosecutor to warrant proceedings came to his knowledge."
"[The defendant] contends that the words 'sufficient in the opinion of the prosecutor to warrant the proceedings' are merely descriptive of the evidence, and that the prosecutor would not have to form his opinion before time begins to run. I accept that submission because otherwise the prosecutor, in full possession of all relevant information, can prevent time from running simply by not applying his mind to the case. Section 11(2) is an exception to the normal rule that summary offences should be prosecuted within six months. As an exception in favour of the prosecution it should be strictly construed. The draftsman could have provided that proceedings for an offence under subsection (1) 'may be brought within a period of six months from the date on which the prosecution forms the opinion that there is sufficient evidence to warrant proceedings' but he did not do so."
"22. The clear purpose of section 6(3) is to achieve certainty, both for the prosecutor and for the defendant, and to prevent what would otherwise be an exercise in discovery of the prosecuting process as to when a particular information came to hand and as to when decisions as to its sufficiency could or should have been made. Clearly any such possibility in the context of this sort of provision would be an intolerable burden to the prosecution and a cog on the wheels of justice at summary level. 23. It has to be remembered, too, that the test in section 6(1) is whether the date on which evidence 'sufficient in the opinion of the prosecutor to warrant the proceedings has come to his knowledge'. As in many other matters concerning the prosecution of offences there is a margin of judgment given to the prosecutor. In my view, there is no way of going behind section 6(3) as suggested by Ms Gumbel so as to negate its clear provision that a certificate for this purpose is conclusive, save possibly in the two exceptional cases to which I have referred."