(1)If at any time while a condition under section 135 or 136 (a “grant condition”) remains in force with respect to a qualifying dwelling—
(a)the owner of the dwelling to which the condition relates pays the amount of the grant to the local housing authority by whom the grant was made, or
(b)a mortgagee of the interest of the owner in that dwelling being a mortgagee entitled to exercise a power of sale, makes such a payment, or
(c)the local housing authority determine not to demand repayment on the breach of a grant condition, or
(d)the authority demand repayment in whole or in part on the breach of a grant condition and that demand is satisfied,
the grant condition and any other grant conditions shall cease to be in force with respect to that dwelling.
(2)An amount paid by a mortgagee under subsection (1)(b) shall be treated as part of the sums secured by the mortgage and may be discharged accordingly.