In Blomberg, Johan Daniel v Khan Zhi Yan  SGHC 238, the General Division of the High Court of Singapore (per See Kee Oon J) considered the legal principles on when a consent order may be set aside: -.
He distinguished between (a) a “contractual consent order” and an “uncontested consent order”; and (b) a “procedural consent order” and a “substantive consent order”.
In sum, contractual consent orders can only be interfered with on grounds of contract law vitiating factors. The court has no residual discretion to set aside or not enforce substantive contractual consent orders.
First, there is a conceptual distinction between a “contractual consent order” and an “uncontested consent order”.
In the former, there is a contract made between the parties.
In the latter, parties do not object to the order, in which case there is no real contract between the parties.
In order to ascertain which category a consent order falls under, the court would have regard to, among other factors, whether there was prior negotiation or clear written correspondence and whether there was consideration exchanged between the parties for a valid contract.
The second conceptual distinction is between “procedural” and “substantive” consent orders.
This concerns whether a consent order deals with the parties’ procedural rights in the litigation process, or parties’ substantive rights in the suit.
A contractual consent order should only be set aside pursuant
to ordinary principles of contract law, and accordingly only the existence of
recognised vitiating factors in contract law can justify setting aside such
contractual consent orders.
Where a contractual consent order is set aside due to the existence of vitiating factors, it is set aside ab initio.
The court does not retain a residual discretion to set aside substantive contractual consent orders in order to prevent injustice. The Court of Appeal in Turf Club Auto Emporium stated that the court’s residual discretion does not extend to not enforcing substantive contractual consent orders, and much less to setting aside such orders.
In coming to that decision, the Court of Appeal had regard to: (a) the principle of finality; (b) the fact that parties entered into consent orders not to enable the court to exercise supervisory jurisdiction but rather to be able to enforce the judgment; (c) consistency in how the law regards consent; and (d) the demands of fairness.
The Court in this case considered that O 3 r 2(2) of the ROC 2021 likely forms the juridical basis for setting aside a contractual consent order if there are vitiating factors, although this point is left for future consideration.