De Facto Relationships Act 1991

A court may make an order annulling a declaration under section 10:

on the application of a person who applied for the declaration, or could have applied for it, or is affected by it; and

if satisfied that new facts or circumstances have arisen which have not previously been disclosed to the court, and could not by the exercise of reasonable diligence have been so disclosed.

If any person whose interests would, in the opinion of the court, be affected by the making of such an order is not present or represented, and has not been given the opportunity to be present or represented, at the hearing of the application, the court may, if it thinks that that person ought to be present or represented at the hearing, adjourn the hearing to enable that person to be given that opportunity.

A declaration ceases to have effect on the making of an order of annulment, but the annulment does not affect anything done in reliance on the declaration before the making of the order.

Where a court makes an order annulling a declaration, it may if it thinks it would be just and equitable to do so make such ancillary orders (including orders varying rights with respect to property) as may be necessary to place any person affected by the annulment in the same position (as far as practicable) as that person would have been in if the declaration had not been made.