Presumably you have it written in the tenncy agreement that all the bills are included in the rent?
If so, i would write, recorded delivery to each supplier who is owed, with a copy of the contract explaining the problem, and that you are trying to get the landlord to resolve the issue, and giving the landlords contact details so they can pursue him themselves.
At the same time, i would get copies of the letters from the suppliers, and send them recorded delivery , with a copy of the tenancy agreement highlighting the clause that specifies he is paying the bills. Also include a letter, politely detailing the occassions where you have contacted him about it. explain that he is in breach of contract and that unless he pays the bills, and provides proof of such by X date, then you will have no alternative but to withhold the rent in order to pay the bills yourself using this money.