“The leading case on the issue of the appointment of amicus curaie in the context of a family law proceeding is Morwald–Benevides v. Benevides, 2019 ONCA 1023. In it, the Ontario Court of Appeal has found that the following principles apply for the appointment of amicas curiae:
[27] First, the assistance of amicus must be essential to the adequate discharge of the judicial functions in the case: CLA, at para. 47. The stakes must be high enough to warrant amicus. This is a circumstantial determination within the trial judge’s discretion.
[28] Second, a party has the right to self-represent: CLA, at para. 51. However, the trial judge is responsible for ensuring that the trial progresses reasonably. There are situations in which the appointment of amicus might be warranted, such as when the self-represented party is ungovernable or contumelious, when the party refuses to participate or disrupts trial proceedings, or when the party is adamant about conducting the case personally but is hopelessly incompetent to do so, risking real injustice: see, e.g., R. v. Imona-Russel (2019), 145 O.R. (3d) 197, [2019] O.J. No. 1607, 2019 ONCA 252; Zomparelli v. Conforti, [2018] O.J. No. 543, 2018 ONSC 610 (S.C.J.).
[29] Third, relatedly, while amicus may assist in the presentation of evidence, amicus cannot control a party’s litigation strategy, and, because amicus does not represent a party, the party may not discharge amicus: Imona-RusseI, at para. 67
[30] Fourth, the authority to appoint amicus should be used sparingly and with caution, in response to specific and exceptional circumstances: CLA, at para. 47. And see O. (C.C.) v. V. (J.J.), [2019] A.J. No. 992, 2019 ABCA 292, 91 Alta. L.R. (6th) 237, at para. 50. This is in part a recognition of the financial exigencies, which is ultimately a political question under our separation of powers doctrine, as CLA noted at paras. 27-31, 83.
[33] Fifth, the trial judge must consider whether he or she can personally provide sufficient guidance to an unrepresented party in the circumstances of the case to permit a fair and orderly trial without the assistance of amicus, even if the party’s case would not be presented quite as effectively as it would be by counsel: Imona-Russel, at para. 69.
[38] Sixth, it will sometimes, though very rarely, be necessary for amicus to assume duties approaching the role of counsel to a party in a family case. While the general role of amicus is to assist the court, the specific duties of amicus may vary. This is a delicate circumstantial question. If such an appointment is to be made and the scope of amicus’s duties mirror the duties of traditional counsel, care must be taken to address the issue of privilege, as in Imona Russel, at para. 89.
[39] Finally, the order appointing amicus must be clear, detailed and precise in specifying the scope of amicus’s duties. The activities of amicus must be actively monitored by the trial judge to prevent mission creep, so that amicus stays well within the defined limits.”