I think you can have an offence if they do not cooperate Kurnal.
(4) The occupier of the other premises must co-operate with the responsible person for the purposes of paragraph (2).
This (The part you are making reference to from article 17, inserted for the benefit of people who can't be bothered to look) gives them a clear obligation with regards to maintenance by virtue of their tenancy:
Then move on to Article 5:
(4) Where a person has, by virtue of any contract or tenancy, an obligation of any extent in relation to—
(a) the maintenance or repair of any premises, including anything in or on premises; or
(b) the safety of any premises,
that person is to be treated, for the purposes of paragraph (3), as being a person who has control of the premises to the extent that his obligation so extends.
Therefore article 5 can define them as a responsible person for those matters. As soon as we have a RP defined the offences part is just the same whether it is an employer, self employed, person having control etc.