What is the test on an application to strike?

The test on an application to strike is whether or not the defendants' pleadings disclose a cause of action. The authority for that is Hunt v. Carey Inc., 1990 CanLII 90 (SCC), [1990] 2 S.C.R. 959. The authorities direct the court to be cautious on such an application, and to be reluctant to strike. The court will strike only if it is plain and obvious that the claim cannot proceed. In other words, do the pleadings of the defendants disclose a cause of action against the third party and is it plain and obvious that, as is argued by the third party, the pleadings do not disclose such a cause of action.