In Theratechnologies inc. v. 121851 Canada inc.,37 Justice
Abella, writing for a unanimous court, described the test for leave
as a “robust deterrent screening mechanism”, which is designed
to prevent “costly strike suits and litigation with little chance of
success”. The reasonable possibility of success requirement of the
leave test is a meaningful but low threshold, merits-based test
that is more than a superficial examination of the merits of the
plaintiff’s statutory cause of action but a meaningful examination
of the evidence to ensure that the action has some merit.38 While
relatively low, the test for leave is a different and more robust
standard than the general threshold for the certification or
authorization of a class action.39
 The leave test is meant to create a robust deterrent screening
mechanism with a reasoned consideration of the evidence from both
parties so that cases without merit are prevented from proceeding.40
 The motion judge should be cognizant of the fact that full
production has not been made and that the defendant may have
relevant documentation and evidence that is not before the court.41
A full analysis of the evidence is unnecessary, and the plaintiff need
only provide a plausible analysis of the applicable legislative provisions and some credible evidence in support of the claim sufficient
to persuade the court that there is a reasonable possibility that the
action will be resolved in the plaintiff’s favour.42 However, the
court must do more than simply ascertain whether the plaintiff has
presented evidence of a triable issue; using the record of affidavit
evidence and cross-examinations, the court is entitled to weigh the
37 Supra, at para. 39.
38 Musicians’ Pension Fund of Canada (Trustees of) v. Kinross Gold Corp., supra
(C.A.), affg  O.J. No. 5071, 2013 ONSC 6864 (S.C.J.); Green v. CIBC, supra
(C.A.), varg supra (S.C.J.), vard supra (S.C.C.), leave to appeal refused (2011),
105 O.R. (3d) 212,  O.J. No. 656 (Div. Ct.); Bradley v. Eastern Platinum
Ltd.,  O.J. No. 1603, 2016 ONSC 1903 (S.C.J.), at para. 51.
39 Theratechnologies inc. v. 121851 Canada inc., supra, at para. 35; Goldsmith
v. National Bank of Canada (2016), 128 O.R. (3d) 481,  O.J. No. 146,
2016 ONCA 22, at paras. 27-33, affg (2015), 126 O.R. (3d) 191,  O.J.
No. 2543, 2015 ONSC 2746 (S.C.J.).
40 Theratechnologies inc. v. 121851 Canada inc., supra, at para. 38; Mask v.
Silvercorp Metals Inc., supra, at paras. 42-43 (C.A.), affg (S.C.J.), supra.
41 Rahimi v. SouthGobi Resources Ltd. (2017), 137 O.R. (3d) 241,  O.J.
No. 4829, 2017 ONCA 719, at paras. 45-49.
42 Theratechnologies inc. v. 121851 Canada inc., supra, at paras. 38-39; Green
v. CIBC, supra, at paras. 122, 147 and 212 (S.C.C.); Goldsmith v. National
Bank of Canada, supra (C.A.), at para. 34, affg supra (S.C.J.).