A decree granted in an action for aliment brought before or after the commencement of this Act may, on an application by or on behalf of either party to the action, be varied or recalled by an order of the court if since the date of the decree there has been a material change of circumstances.

Without prejudice to the generality of subsection (1) above, the making of a F2maintenance assessmentF2maintenance calculation with respect to a child for whom the decree of aliment was granted is a material change of circumstances for the purposes of that subsection.

The provisions of this Act shall apply to applications and orders under subsection (1) above as they apply to actions for aliment and decrees in such actions, subject to any necessary modifications.

On an application under subsection (1) above, the court may, pending determination of the application, make such interim order as it thinks fit.

Where the court backdates an order under subsection (1) above, the court may order any sums paid under the decree to be repaid.