What is the test for security for costs in an action brought by a plaintiff against the government?

The plaintiffs relies on the case of Whitty v. Wells [2016] O.J. No. 1696, where the court states at paragraphs 32 and 33: 32 Rule 56.01 lists the most common situations where security for costs is appropriate; but they are not the only situations. In this case, I originally designed a two track process to see the parties move forward with production and mediation on the merits while holding off the government’s proposed motions for summary judgment. Now as a result of the plaintiff’s failure to comply with the schedule, there will likely be a significant hiatus for several months… 33 In the circumstances, it seems to me that an order for security for costs is very much a fitting term of a further extension of time. If the plaintiffs persist in disobeying court orders or if they fail to deliver a proper expert report on a timely basis which I fear is a real likelihood, then a dismissal of the actions and a substantial award of costs of the action against the plaintiffs is indeed very likely…