13.—(1) If a trade union or an employers' association refuses or wilfully neglects to perform a duty imposed on it by or under any of the provisions of Article 10 or 11 or 12 or Schedule 1 the trade union or employers' association shall be guilty of an offence.
(2) Subject to paragraph (3), any offence committed by a trade union or an employers' association under paragraph (1) shall be deemed to have been also committed by—
(a)every officer of that trade union or employers' association who is bound by the rules of the union or association to discharge on its behalf the duty breach of which constitutes that offence; or
(b)if there is no such officer, every member of the principal executive committee of the union or association.
(3) In any proceedings brought against an officer or member by virtue of paragraph (2) in respect of any breach of duty, it shall be a defence for him to prove that he had reasonable cause to believe, and did believe, that some other person who was competent to discharge that duty was authorised to discharge it instead of him and had discharged it or would do so.
(4) A person who wilfully alters or causes to be altered a document which is required for the purposes of any of the provisions of Article 10 or 11 or 12 or Schedule 1, with intent to falsify the document or to enable a trade union or employers' association to evade any of those provisions, shall be guilty of an offence.
(5) For every offence committed under this Article the trade union, employers' association or other person guilty of the offence shall be liable on summary conviction—
(a)in the case of an offence under paragraph (1), to a fine not exceeding level 3 on the standard scale;
(b)in the case of an offence under paragraph (4), to a fine not exceeding level 5 on the standard scale.