Sch. 3 para. 26 in force at 31.12.2020 immediately before the 2019 Regulations come into force, see reg. 1
Subject to the following provisions of this paragraph, in proceedings against a person for an offence to which this paragraph applies it shall be a defence for that person to show that the person took all reasonable steps and exercised all due diligence to avoid committing the offence.
Where in any proceedings against any person for such an offence the defence provided by sub-paragraph (1) involves an allegation that the commission of the offence was due—
to the act or default of another; or
to reliance on information given by another,
that person shall not, without leave of the court, be entitled to rely on the defence unless, not less than seven clear days before the hearing of the proceedings, the person has served a notice under sub-paragraph (3) on the person bringing the proceedings.
A notice under this sub-paragraph must give such information identifying or assisting in the identification of the person who committed the act or default or gave the information as is in the possession of the person serving the notice at the time when that person serves it.
A person shall not be entitled to rely on the defence provided by sub-paragraph (1) by reason of reliance on information supplied by another, unless the person shows that it was reasonable in all the circumstances to have relied on the information, having regard in particular to—
the steps which the person took, and those which might reasonably have been taken, for the purpose of verifying the information; and
whether the person had any reason to disbelieve the information.
This paragraph applies to an offence under paragraph 3(1) or (4), 4(1), 5(1), 6(6), 11(4) or 13(2).