13. After paragraph 6(8) of that Schedule, there shall be inserted—
“(9) Where—
(a)an order under paragraph 1(2)(a) or (b) for the making or securing of periodical payments in favour of more than one child (“the order”) is in force;
(b)the order requires payments specified in it to be made to or for the benefit of more than one child without apportioning those payments between them;
(c)a maintenance assessment (“the assessment”) is made with respect to one or more, but not all, of the children with respect to whom those payments are to be made; and
(d)an application is made, before the end of the period of 6 months beginning with the date on which the assessment was made, for the variation or discharge of the order,
the court may, in exercise of its powers under paragraph 1 to vary or discharge the order, direct that the variation or discharge shall take effect from the date on which the assessment took effect or any later date.”