3.—(1) Subject to sub-paragraph (2) to (4), in proceedings against a person for an offence under these Regulations it shall be a defence for that person to show that he took all reasonable steps and exercised all due diligence to avoid committing the offence.
(2) Where in any proceedings (which in Scotland include the trial diet) against any person for such an offence the defence provided for by sub-paragraph (1) involves an allegation that the commission of the offence was due—
(a)to the act or default of another, or
(b)to reliance on information given by another,
that person shall not, without the leave of the court, be entitled to rely on the defence unless, not less than seven clear days before the hearing of the proceedings (or, in Scotland, the trial diet) he has served a notice under sub-paragraph (3) on the person bringing the proceedings.
(3) A notice under this sub-paragraph shall give such information identifying or assisting in the identification of the person who is alleged to have committed the act or default or to have given information as is in the possession of the person serving the notice at the time he serves it.
(4) A person shall not be entitled to rely on the defence provided by sub-paragraph (1) by reason of his reliance on information supplied by another, unless he shows that it was reasonable in all the circumstances for him to have relied on the information, having regard in particular—
(a)to whether he had any reason to disbelieve the information, and
(b)in the case of a supplier, to the steps which he took, and those which might reasonably have been taken, for the purpose of verifying the information.