Although the lease may seem to be defective on a reading of the lease you should bear in mind that if the lease was granted on or after 3 October 1980 it will be probably be compliant with the provisions of the Housing Act 1985 (right to buy properties), which have standard covenants implied into such leases. These implied covenants are found in Schedule 6 of the 1985 Act. Get your conveyancer to check Schedule 6 to see if those provisions cover the defects[s] that concern you.
More information you might find useful:
Still not found the answer?
Contact LEASE to have your enquiry dealt with by one of our experienced advisers