Mootness - Procedure. Right to Life Association of Toronto v. Canada (Attorney General)
In Right to Life Association of Toronto v. Canada (Attorney General) (Fed CA, 2022) the Federal Court of Appeal considered when mootness may be raised by a party:
 The appellants submit that the Court should not entertain the respondent’s motion because the respondent could have raised mootness earlier and should not be permitted to raise this "“new issue”" for the first time on appeal. I disagree. While the desirability of addressing mootness at an early stage is obvious, mootness may be raised at any time. It may be raised by the Court if the parties do not raise it: Canadian Union of Public Employees (Air Canada Component) v. Air Canada, 2021 FCA 67,  F.C.J. No 286 (Q.L.) [CUPE]; Hakizimana v. Canada (Public Safety and Emergency Preparedness), 2022 FCA 33, 87 Imm. L.R. (4th) 175 [Hakizimana].. Roberts (Re)
In Roberts (Re) (Ont CA, 2022) the Court of Appeal, hearing an NCR (not criminally responsible) case, noted that the Court of Appeal did not generally decide moot cases:
 As a general principle, this court does not decide moot cases: Borowski v. Canada (Attorney General), 1989 CanLII 123 (SCC),  1 S.C.R. 342; Abernethy (Re), 2021 ONCA 509, 2021 CarswellOnt 10355, at para. 4; Halat (Re), 2019 ONCA 112, 2019 CarswellOnt 1885, at paras. 7-9. This principle applies especially to Review Board cases. As this court noted in Halat, at para. 11, “because of the continuing jurisdiction of the Board over the appellant, it is important that this court only review dispositions of the Board where it can give a remedy for any reviewable error.”. Ontario (Provincial Police) v. Mosher
In Ontario (Provincial Police) v. Mosher (Ont CA, 2015) the Court of Appeal sets out the court procedure when a claim of mootness occurs:
 The approach taken by a court confronted with a claim of mootness involves two steps. The first step requires a determination whether the essential tangible and concrete dispute – the lis inter partes – has disappeared and the issues have become academic. If the response at this first step is affirmative, the second step requires the court to decide whether it should exercise its discretion to hear the case: Borowski, at p. 353; Mental Health Centre, at para. 36.