An elderly friend has rented out his field on a long term basis. There has never been a tenancy agreement and rent was paid annually by cheque until recently, since when it has been paid in cash with no written record. Would it be possible for the tenant to claim ownership of the field at some point?
Yes in theory, especially since it may well be the case that your friend’s ownership of the field isn’t registered at the Land Registry. If it is registered then your friend would be notified if someone staked a claim to own it, and would have two years in which to remove the tenant. Without this safeguard, and without a tenancy agreement or record of rent payments, the tenant could claim he has occupied the field unchallenged for 12 years and claim ownership through adverse possession.