683. Transfer of statutory tenancy.

A statutory tenancy1 cannot be assigned2. Where, however, it is so agreed in writing between the statutory tenant ('the outgoing tenant') and a person proposing to occupy the dwelling3 ('the incoming tenant'), the incoming tenant is deemed to be the statutory tenant of the dwelling as from such date as may be specified in the agreement ('the transfer date')4. Such an agreement does not have effect unless the landlord5 is a party thereto and, if the consent of any superior landlord would have been required to an assignment of the previous contractual tenancy, unless the superior landlord is a