Hazelton Lanes Inc. v. 1707590 Ontario Limited, 2014 ONCA 793:
 The test for reasonable apprehension of bias is that set out in de Grandpré J.’s dissenting opinion in Committee for Justice and Liberty v. Canada (National Energy Board) (1976),  1 S.C.R. 369 (S.C.C.), at pp. 394-95, which reads as follows:
[T]he apprehension of bias must be a reasonable one, held by reasonable and right minded persons, applying themselves to the question and obtaining thereon the required information…. [The] test is “what would an informed person, viewing the matter realistically and practically – and having thought the matter through – conclude. Would he think that it is more likely than not that [the decision-maker], whether consciously or unconsciously, would not decide fairly.”
 The Supreme Court of Canada has repeatedly endorsed this test. In his reasons in R. v. S. (R. D.),  3 S.C.R. 484, Cory J. explained, at para. 111, that the test set down by de Grandpré J. in Committee for Justice and Liberty contains a “two-fold objective element”: not only must the person considering the alleged bias be reasonable, but “the apprehension of bias itself must also be reasonable in the circumstances of the case.”
 It has also been held that, in order to maintain public confidence in the administration of justice, the appearance of judicial impartiality is as important as the reality. In Metropolitan Properties Co. (F.G.C.) Ltd. v. Lannon,  3 All E.R. 304 (C.A.), at p. 310, Lord Denning M.R. stressed the importance of the appearance of judicial impartiality. He said:
[I]n considering whether there was a real likelihood of bias, the court does not look at the mind of the justice himself.... It does not look to see if there was a real likelihood that he would, or did, in fact favour one side at the expense of the other. The court looks at the impression which would be given to other people. Even if he was as impartial as could be, nevertheless, if right-minded persons would think that, in the circumstances, there was a real likelihood of bias on his part, then he should not sit. And if he does sit, his decision cannot stand.
 This passage was cited with approval by Major J. in his dissenting reasons in S. (R. D.), at para. 11, and by this court in Benedict v. Ontario (2000), 51 O.R. (3d) 147. In Benedict, this court added, at para. 20:
We note that while Lord Denning M.R. spoke in terms of a “real likelihood” rather than a “reasonable apprehension”, in National Energy Board de Grandpré J. took care to state that such variations in the expression used should not generally be treated as involving any substantive difference in the approach to be taken. “Reasonable apprehension”, “real likelihood”, “reasonable likelihood” and “reasonable suspicion” amount to the same standard.
 This reasoning accords with the decision of Lord Nolan in R. v. Bow Street Metropolitan Stipendiary Magistrate et al.,  1 All E.R. 577 (H.L.), at p. 592: “[I]n any case where the impartiality of a judge is in question the appearance of the matter is just as important as the reality.”
 The appearance of impartiality was emphasized in Wewaykum Indian Band v. Canada,  2 S.C.R. 259, at para. 66:
[W]here disqualification is argued, the relevant inquiry is not whether there was in fact either conscious or unconscious bias on the part of the judge, but whether a reasonable person properly informed would apprehend that there was.
 A review of this court’s recent statements in Chippewas of Mnjikaning First Nation v. Ontario, 2010 ONCA 47, 265 O.A.C. 247, leave to appeal to S.C.C. refused,  S.C.C.A. No. 91, at paras. 229-30, and Marchand (Litigation Guardian of) v. Public General Hospital Society of Chatham (2000), 51 O.R. (3d) 97, leave to appeal to S.C.C. refused,  S.C.C.A. No. 66, at para. 131, reveals the following principles for assessing a claim of reasonable apprehension of bias that are particularly applicable in this case:
· “Impartiality reflects the state of mind in which the judge is disinterested in the outcome and is open to persuasion by the evidence and submissions. In contrast, bias reflects a state of mind that is closed or predisposed to a particular result on material issues”: Marchand, at para. 131.
· The threshold for a finding of reasonable apprehension of bias is high. “Courts presume that judges will carry out their oath of office”: Marchand, at para. 131.
· To determine that a reasonable apprehension of bias exists requires “a fact-specific inquiry” that considers “the facts and circumstances of a particular trial”: Chippewas, at para. 230.
· “The party alleging reasonable apprehension of bias has the onus of proving it on the balance of probabilities”: Marchand, at para. 131.
· The grounds for finding a reasonable apprehension of bias must be substantial; establishing an allegation of judicial bias requires “cogent evidence”: Marchand, at para. 131.
 If a judge’s words or conduct give rise to a reasonable apprehension of bias, it colours the entire trial. Therefore, on appeal, “a finding of actual or apprehended bias will ordinarily result in a new trial”: Marchand, at para. 131.