A tenancy is not a protected tenancy if under the tenancy the dwelling-house is bona fide let at a rent which includes payments in respect of board or attendance.

For the purposes of subsection (1) above, a dwelling-house shall not be taken to be bona fide let at a rent which includes payments in respect of attendance unless the amount of rent which is fairly attributable to attendance, having regard to the value of the attendance to the tenant, forms a substantial part of the whole rent.