The landlord may, subject to the provisions of this section, serve on the tenant at any time a written notice requiring him—
and informing the tenant of the effect of this section and of section 153(1), (2) and (4) (landlord's second notice to complete and its effect).
The period stated in a notice under this section shall be such period (of at least 56 days) as may be reasonable in the circumstances.
A notice under this section shall not be served earlier than twelve months after the service of the notice under section 146 (landlord's notice admitting or denying right).
A notice under this section shall not be served if—
In this section "relevant matters" means matters relating to the grant and to securing the redemption of the landlord's share.