See Practice Note: What happens to an underlease on termination of the lease? which covers consensual termination, surrender and grant of a new lease, exercise of a break, issues for the tenant, security of tenure, forfeiture and relief from forfeiture. The general common law principle is, when a lease comes to an end any underlease/sub-lease automatically terminates. Statute intervenes on surrender of a lease. It is a consensual termination and the tenant's interest is deemed to pass to the landlord subject to the rights of the undertenant under section 139 of the Law of Property Act 1925 (LPA 1925). The effect of a merger is the same. Under