A party has a duty to the court and to the other party to provide full, frank and clear disclosure of all material facts (whether in contested proceedings or otherwise) and to keep such disclosure up to date until the final disposition of the case by the court.
The duty of disclosure exists where parties exchange disclosure voluntarily, whether or not in court pleadings such as a Form E. It could even continue beyond the making of the substantive order, in circumstances where one party knew of a new event or any other circumstance that might arguably be grounds for an appeal. Consequently, a failure by one party to provide full and frank disclosure might allow the other party to challenge a financial remedy order and entitle the court to set it aside.
Fraud or fraudulent non-disclosure
Fraud at the time an order is made can act as a vitiating factor, allowing the non-fraudulent party to challenge the order and entitling the court to set it aside, but it is not every instance of fraud that will justify setting aside an order.
The criteria for setting aside an order for fraudulent non-disclosure: Sharland and Gohil
The Supreme Court has recently considered the criteria for setting aside an order for fraudulent non-disclosure in the cases of Sharland v Sharland  UKSC 60 and Gohil. The Supreme Court overturned the previous decisions of the Court of Appeal, deciding that in cases where fraudulent non-disclosure is found, the order will be set aside unless both the following apply:
The court is satisfied that where a consent order is made, the fraud would not have influenced a reasonable person to agree to it.
Had it known at the time the order was made what it knows now, the court would not have made a significantly different order, whether or not the parties had agreed to it.
The burden of satisfying the court of this exception lies with the perpetrator of the fraud.