HL 17 February 2000. In 1994 appellant council C granted respondent tenant B and H a secure tenancy satisying the requirements of the Housing Act 1985 Part 1V. H moved out in 1996. C refused the transfer of the joint tenancy to R as a sole tenant. H executed a deed releasing all beneficial interest in the joint tenancy to R. C refused to accept validity of the deed on the grounds that under s91(1) of the 1985 act a secure tenancy could not be assigned. R appealed to CA. CA declared that deed was effective recognising R as the sole tenant under the secure tenancy. C appealed to HL. Appeal allowed . Held that the deed of release was ineffective in transferring the tenancy to R.