Where a secure tenant has served—
a notice under section 146A(1)(a) stating that he intends to pursue his claim to exercise the right to acquire on rent to mortgage terms, and the amount of the initial payment which he proposes to make, or
a notice under section 146A(3)(b) varying the amount stated in a notice under section 146A(1)(a),
the landlord shall, as soon as practicable, serve on the tenant a written notice complying with this section.
The notice shall state—
the landlord's share on the assumption that the amount of the tenant's initial payment is that stated in the notice under section 146A(1)(a) or, as the case may be, section 146A(3)(b), and
the amount of the initial discount on that assumption,
determined in each case in accordance with section 148.