What is the legal test for overturning a consent order?

The ability of the court to vary a consent order is very limited, as set in Shackleton v. Shackleton, 1999 BCCA 704, at para. 12: A consent order is a formal expression of an agreement between the parties. Where parties intend to finally dispose of the issues between them, a consent order will operate as a final judgment... For the same reason that courts enforce settlement agreements, to provide certainty to parties settling disputes, consent orders are not easily altered. Subject to statutory provisions otherwise a consent order may be set aside or altered in substance only in circumstances which justify the same treatment to the underlying contract …