Where the tenant of any premises, consisting of a house or part of a house, has sublet a part but not the whole of the premises, then, as against his landlord or any superior landlord, no part of the premises shall be treated as not being a dwelling-house let on or subject to a protected or statutory tenancy by reason only that—
the terms on which any person claiming under the tenant holds any part of the premises include the use of accommodation in common with other persons; or
part of the premises is let to any such person at a rent which includes payments in respect of board or attendance.
Nothing in this section shall affect the rights against, and liabilities to, each other of the tenant and any person claiming under him, or of any 2 such persons.