(1) If a health and safety representative, or deputy health and safety representative (if any), represents a work group of workers carrying out work for 2 or more persons conducting businesses or undertakings--(a) the costs of the representative exercising powers and performing functions under this Act, and(b) the costs referred to in section 72 (2) (b),for which any of the persons conducting those businesses or undertakings are liable must be apportioned equally between each of those persons unless they agree otherwise.
(2) An agreement to apportion the costs in another way may be varied at any time by negotiation and agreement between each of the persons conducting the businesses or undertakings.