(1) Any choice made by the parties under regulation 4 must be expressed or demonstrated with reasonable certainty by the terms of the contract or the circumstances of the case.
(2) Where the parties to the contract may choose the applicable law under regulation 4, and where the risk to which the contract relates is covered by Community co-insurance (within the meaning of the Solvency 2 Directive, co-insurers other than the leading insurer (within the meaning of that Directive) are not to be treated as parties to the contract.