385. Building leases.

In all leases1, whether made before, on or after 1 January 1926, containing a covenant, condition or agreement against assigning, underletting, charging or parting with the possession of the demised premises or any part of them without licence or consent, such covenant, condition or agreement is deemed, notwithstanding any express provision to the contrary, to be subject (if the lease is for more than 40 years and is made in consideration wholly or partially of the erection, or the substantial improvement, addition or alteration, of buildings, and the lessor is not a government department or a local or public