[2002] EWCA Civ 666, 17 May 2002. Appellant tenant (H) held a lease of commercial premises from the respondent landlord (A) which included a covenant by the tenant not to underlet the premises without first obtaining the landlord's consent. The covenant was subject to a proviso that required the rent of any underlease not to be less than full market rent, and for the underlease to contain covenants in the same terms as the lease. H made an agreement to sublet the premises to L and an underlease was prepared on the same terms as the lease. However, the parties also prepared a personal collateral deed allowing less onerous performance and indemnifying L. When H applied for A's consent, A issued proceedings seeking an order to stop the completion of the proposed underlease and collateral deed and refused H's request for consent to underlet. L withdrew and H counterclaimed that A was in breach of its duty under the Landlord and Tenant Act 1988 s1(3)(a). Counterclaim dismissed and H appealed contending that the provisions in the collateral deed were personal to H and L. "Held": appeal dismissed; the requirements of the proviso were not satisfied by the underlease when the collateral deed was read into it and A therefore was never under any duty under s1(3)(a) of the 1988 Act. View judgment at www.bailii.org.