In reply to The Freewheelin’ Jim182:
If it's a lease car, is he even insured to take it abroad? Think as EU members there was a requirement to cover up to 90 days in other member states - but how we've left.....
If it's a UK policy, no chance they will offer different (more comprehensive) cover abroad than in the UK.
Sounds like you need to take someone else's car, or get in touch with the lease company and pay to add yourself and other members of the group to his policy.