Subject to sub-paragraph (2), in any arbitration to which this Schedule applies, the arbitrator may join as a party to the arbitration any person having an interest in the holding, whether or not such person has applied to become a party to the arbitration, provided that such person consents to be so joined.

Where an apportionment pursuant to a request in a statement under regulation 39(4)(b) is to be carried out by arbitration, any person with an interest in the holding who has refused to sign such a statement as is referred to in regulation 39(4)(a) must be a party to the arbitration.