31.—(1) Where a decision relating to custody is varied or revoked by an authority in the Contracting State in which it was made, any person appearing to the Court to have an interest in the matter may make an application to the Court for an order for variation or revocation of the order of recognition or enforcement of that decision.

(2) Where an application is made under subsection (1) of this section for revocation of an order the Court shall, if it is satisfied that the decision (in respect of which the order of recognition or enforcement was made) has been revoked by an authority in the Contracting State in which it was made, discharge the order and the decision shall cease to be enforceable in the State.

(3) Where an application is made under subsection (1) of this section for variation of an order, the Court may, if it is satisfied that the decision has been varied by an authority in the Contracting State in which it was made and, subject to the grounds of refusal specified in section 28 (1) of this Act, make an order varying the order and a decision so varied shall be of the same force and effect, and as respects the enforcement of the decision so varied, the Court shall have the same powers and proceedings may be taken, as if the decision so varied was a decision of the Court.

(4) The Central Authority in the State shall assist the person referred to in subsection (1) of this section if a request for such assistance, in such form as may be prescribed, is made by him or on his behalf by the Central Authority of the Contracting State in question.