A notice under the Law of Property Act 1925 s.146 could only be validly served if a right of re-entry to leasehold premises had arisen through a particular breach under the provisions of the lease having occurred. There was no authority for the proposition that a s.146 notice could be served before the relevant right to re-entry had occurred, on the basis of an anticipated breach.
For more information see the England and Wales High Court (Queen’s Bench Division) Decisions.