There shall be deducted from the discount an amount equal to any previous discount qualifying, or the aggregate of previous discounts qualifying, under the provisions of this section.
A "previous discount" means a discount given before the relevant time—
on conveyance of the freehold, or a grant or assignment of a long lease, of a dwelling-house by a person within paragraph 7 or 7A of Schedule 4 (public sector landlords) or, in such circumstances as may be prescribed by order of the Secretary of State, by a person so prescribed, or
on conveyance of the freehold, or a grant or assignment of a long lease of a dwelling-house by a person against whom the right to buy was exercisable by virtue of section 171A (preservation of right to buy on disposal to private sector landlord) to a person who was a qualifying person for the purposes of the preserved right to buy and in relation to whom that dwelling-house was the qualifying dwelling-house, or
in pursuance of the provision required by paragraphs 3 to 5 or paragraph 7 of Schedule 6A (redemption of landlord's share), or
in pursuance of the provision required by paragraph 1 of Schedule 8 (terms of shared ownership lease: right to acquire additional shares), or any other provision to the like effect or.
in pursuance of any provision of, or required by, this Part ... by virtue of section 17 of the Housing Act 1996 (the right to acquire).
A previous discount qualifies for the purposes of this section if it was given—
to the person or one of the persons exercising the right to buy, or
to the spouse , or civil partner, of that person or one of those persons (if they are living together at the relevant time), or
to a deceased spouse , or deceased civil partner, of that person or one of those persons (if they were living together at the time of the death);
and where a previous discount was given to two or more persons jointly, this section has effect as if each of them had been given an equal proportion of the discount.
An order under this section—
may make different provision with respect to different cases or descriptions of case, including different provision for different areas, and
shall be made by statutory instrument which shall be subject to annulment in pursuance of a resolution of either House of Parliament.
In this section "dwelling-house" includes any yard, garden, outhouses and appurtenances belonging to the dwelling-house or usually enjoyed with it.