The Applicants, the Legal Aid Society of Alberta (“LASA”), Calgary Legal Guidance (“CLG”) and the Canadian Civil Liberties Association (“CCLA”) each applied pursuant to Rule 14.58 for permission to intervene on the Appeal. The Appeal concerned various provisions of the Mental Health Act, RSA 2000, c M-13 (the “Mental Health Act”), and whether or not they contravened sections of the Canadian Charter of Rights and Freedoms. The Appellant (Respondent to the Applications to intervene) opposed the Applications of CLG and CCLA but did not oppose LASA’s Application. Justice Antonio found the LASA met the test for intervention and allowed their Application.

Justice Antonio applied the assessment criteria identified in Styles v Canadian Association of Counsel to Employers, 2016 ABCA 218. Justice Antonio also noted that the participation of the proposed intervenor at the Trial level was not determinative of the Application: that the proposed intervenor needs to apply anew, and that the intervenor’s role at Trial can be a favourable factor after considering: a) the role taken by the intervenors at the Trial level; b) whether the submissions of the intervenors were necessary or helpful in informing the Decision being reviewed; c) whether the issues on appeal are the same as in the Court below, or whether the issues as framed on appeal could continue to impact the Applicant’s interests; and d) whether the particular perspectives of the Applicants could continue to inform the discussion as now framed on appeal.

CLG was an intervenor at the Trial level, who described its perspective as being valuable and unique to the Court given its experience providing legal services and advocacy on behalf of clients who were frequently subject to the impugned provisions of the Mental Health Act. Justice Antonio noted that despite CLG not being directly affected by the Appeal, this consideration was only one factor among many, noting that part of the assessment for granting leave to intervene was asking whether the intervenor “has some special expertise or insight”. Justice Antonio found that CLG’s role in the community provided it unique knowledge and insight which would be of assistance to the Court. Justice Antonio also found that CLG’s prior status as intervenor at Trial favoured its Application and noted that the risk of additional delay or overlap of submissions could be managed through the imposition of conditions. Justice Antonio found that there would be no realistic possibility of prejudice to the parties flowing from CLG’s intervention. Accordingly, CLG’s Application for intervenor status was granted.

CCLA indicated its submissions would focus on high level and conceptual questions regarding the constitutionality of detention powers granted by the state. Justice Antonio found that these submissions could do more to obscure the issues than to illuminate the answers and found that the high level and philosophical nature of the proposed submissions would be of assistance if the issues concerned the development of the common law, but because the issues were around the constitutionality of legislation, the proposed submissions risked turning the Courtroom into a legislative arena. Justice Antonio found that CCLA’s topics exceeded the scope of the Appeal, which was impermissible without leave of the Court. Accordingly, CCLA’s Application for intervenor status was denied.