A judge affected by actual bias would be unable to comply with the Judicial Oath, and would be disqualified from sitting. In such a case, the question for determination is whether there is bias in fact.
The test for determining whether a judge should disqualify himself or herself by reason of apprehended bias is “whether a fair-minded lay observer might reasonably apprehend that the judge might not bring an impartial and unprejudiced mind to the resolution of the question the judge is required to decide”: Johnson v Johnson (2000) 201 CLR 488 at , affirmed in Ebner v Official Trustee in Bankruptcy (2000) 205 CLR 337; applied in Michael Wilson & Partners Ltd v Nicholls (2011) 244 CLR 427; distinguished in British American Tobacco Australia Services Ltd v Laurie (2011) 242 CLR 283; see also Slavin v Owners Corporation Strata Plan 16857  NSWCA 71; Barakat v Goritsas (No 2)  NSWCA 36 and Isbester v Knox City Council (2015) 89 ALJR 609.
As to the former association of the judge with legal representatives and litigants, see Bakarich v Commonwealth Bank of Australia  NSWCA 43. As to the relevance of non-disclosure to issues of apprehended bias, see Whalebone v Auto Panel Beaters & Radiators Pty Ltd (in liq)  NSWCA 176. As to a party being a member of the trial court, see Rouvinetis v Knoll  NSWCA 24.
Present authority supports the proposition that an application for disqualification can be made without the filing of a formal motion (Barton v Walker  2 NSWLR 740; Bainton v Rajski (1992) 29 NSWLR 539), although there have been instances where a motion has been presented.
Such authority also supports the view that such an application should be determined by the judge whose disqualification is sought, and should not involve a contest on the facts: Australian National Industries Ltd v Spedley Securities Ltd (in liq) (1992) 26 NSWLR 411 at 436; and Wentworth v Graham  NSWCA 240.
As to the approach to be adopted where there are disputed issues of fact, see CUR24 v DPP (2012) 83 NSWLR 385. In that case, it was held that where there is plausible evidence as to an out of court statement or other conduct of a judicial officer, the relevant principles do not require a court exercising appellate or supervisory jurisdiction to first resolve, by making findings of fact, any dispute about what was said or done before applying the fair-minded bystander test. Rather, the objective assessment called for by the test should take account of the dispute and whether the evidence, if accepted, is sufficient to give rise to a reasonable apprehension of bias: at , . A judge asked to disqualify himself or herself may need to apply the fair-minded observer test in respect of the evidence, in other words, unless the hypothetical observer would reject the evidence as entirely implausible the judge should consider whether, if accepted, it had the relevant quality to raise a reasonable apprehension of bias: , , . The denial of a judge alleged to have made a relevant statement cannot settle the question which depends upon the view of a fair-minded observer: .
A refusal by a judge to accede to an application for disqualification can be relied upon as a ground of appeal in relation to the substantive judgment. However, the conventional view has formerly been that no appeal lies from the rejection of a refusal application as such although a litigant could usually find an interlocutory order upon which to base an appeal: Barton v Walker and Barakat v Goritsas  NSWCA 8 at .
Following strongly expressed obiter dicta in Michael Wilson & Partners Ltd v Nicholls (2011) 244 CLR 427 at – and the decision of the Court of Appeal in Barakat v Goritsas (No 2)  NSWCA 36 that is no longer the position. Further, “it will frequently be appropriate to grant leave to appeal, assuming the challenge is not patently untenable and where a long and costly trial would be avoided if the decision below were incorrect”: Barakat v Goritsas (No 2) at .
Failure to seek such leave may found an issue of waiver: Michael Wilson & Partners Ltd v Nicholls at –.
In respect of refusal by judicial officers of the District Court and Local Court the discretionary remedy of an order in the nature of prohibition may be available.
Generally an application should be made as soon as reasonably practicable after the party seeking disqualification becomes aware of the relevant facts. Otherwise the right to do so may be waived: Vakauta v Kelly (1989) 167 CLR 568; Cassegrain v Commonwealth Development Bank of Australia Ltd  NSWCA 260 and Royal Guardian Mortgage Management Pty Ltd v Nguyen (2016) 332 ALR 128;  NSWCA 88 per Basten JA at –.
Where there are matters that might properly arise for consideration, which are known to the judge, it is desirable that they be drawn to the attention of the parties, even if it is believed that they are aware of them: S & M Motor Repairs Pty Ltd v Caltex Oil (Australia) Pty Ltd (1988) 12 NSWLR 358 and Dovade Pty Ltd v Westpac Banking Corporation (1999) 46 NSWLR 168 at –.
In Laws v Australian Broadcasting Tribunal (1990) 170 CLR 70, the High Court recognised that there are exceptions for necessity, or where there are special circumstances, or where there is consent. For a discussion on the exceptions, see Australian National Industries Limited v Spedley Securities Ltd (in liq), above.
An indication by a party that it wishes a judge to disqualify himself or herself is not of itself a proper ground for the judge to recuse: Fitzgerald v Director of Public Prosecutions (1991) 24 NSWLR 45.
Judges are required to discharge their professional duties unless disqualified by law. They should not accede too readily to applications for disqualification, otherwise litigants may succeed in effectively influencing the choice of judge in their own cause: see Re JRL; Ex p CJL (1986) 161 CLR 342 at 352; Attorney General of New South Wales v Lucy Klewer  NSWCA 295; Ebner v Official Trustee, above, at –; and Raybos Australia Pty Limited v Tectran Corporation Pty Ltd (1986) 6 NSWLR 272.
Where a legal representative does object to the conduct of a judge, or contends actual or apprehended bias on the part of the judge, there is an obligation to endeavour to have those objections and contentions noted and recorded.
Inter alia, this may assist in a correction of an attitude which has possibly gone too far; at the least it will make the complaint easier for resolution if the matter goes to appeal: Goktas v GIO of NSW (1993) 31 NSWLR 684.
The fact that a judge was a customer of a bank which is a party to litigation is normally not a ground for disqualification unless the judge has some special connection with the bank or is in a position of obligation toward, or animus against, the bank: Dovade Pty Ltd v Westpac Banking Corporation, above.
The fact that the judge, or a close family member, holds shares in a litigant party is normally not a ground for disqualification, unless the value or income stream of the shares could be affected by the outcome of the litigation: Dovade Pty Ltd v Westpac Banking Corporation and see Ebner v Official Trustee, above.
The fact that the judge has a direct pecuniary interest in the proceedings will however lead to automatic disqualification: Dimes v Proprietors of Grand Junction Canal Pty (1852) 10 ER 301 and Dovade Pty Ltd v Westpac Banking Corporation.
The fact that the trial judge has expressed views in previous decisions, or in extra-judicial publications in relation to the kind of litigation before the court, which may have questioned an existing line of authority is not normally a reason for disqualification unless those views were expressed with such trenchancy, or in such unqualified terms, as to suggest that the judge could not hear the case with an “open mind”: Timmins v Gormley  1 All ER 65, Newcastle City Council v Lindsay  NSWCA 198 and Gaudie v Local Court of New South Wales  NSWSC 1425 at  ff.
The fact that the judge has made findings in related proceedings which are critical of the recollection, credit and behaviour of those who are also parties to a case in which the same issues of fact and credit would arise for determination, will normally be a ground for disqualification: Australian National Industries Ltd v Spedley Securities Ltd (in liq), above, and Livesey v NSW Bar Association (1983) 151 CLR 288. Express acknowledgment by a judge who is asked to try an issue that he or she has previously determined that different evidence may be led at the later trial may be insufficient to remove the impression that the judge’s previous views might influence the determination of the same issue in the later trial: see British American Tobacco Australia Services Ltd v Laurie (2011) 242 CLR 283 where a judge was disqualified after making relevantly unqualified findings of serious fraud against a party. For a case where a series of undisclosed ex parte hearings did not support a finding of apprehended bias, see Michael Wilson & Partners Ltd v Nicholls (2011) 244 CLR 427.
The fact that the judge is related to a party, or to one of the party’s legal representatives, at least where that legal representative is actually involved in the litigation, will normally be a ground for disqualification. However, where association with somebody with an interest in the litigation is relied upon there must be shown to be a logical connection between the matter complained of and the feared deviation from impartial decision making: Smits v Roach (2006) 227 CLR 423.
The fact that a prior complaint has been made to the Independent Commission Against Corruption, or to some other body such as the Judicial Commission or the Bar Association, in relation to the judge, has also arisen for consideration: Briscoe-Hough v AVS Australian Venue Security Services Pty Ltd  NSWCA 51; see also Attorney General of NSW v Klewer, above.
The fact that the judge knows a party or witness may be a ground for disqualification, depending upon the degree and the circumstances of the acquaintanceship and association.
The fact that the judge has acted in a professional capacity in another matter or matters for a party will not normally be a ground for disqualification: Re Polites; Ex p Hoyts Corporation Pty Ltd (1991) 173 CLR 78 and Australian National Industries v Spedley Securities Ltd (in liq), above.
The statement of findings at an interlocutory stage in terms of finality, for example, in relation to the admissibility of evidence where those findings are related to the ultimate issue in the case, will normally give rise to disqualification: Kwan v Kang  NSWCA 336.
An association may give rise to a reasonable apprehension of bias without there being a connection between the association and one of the issues in dispute: Murlan Consulting Pty Ltd v Ku-ring-gai Municipal Council  NSWCA 300.
For an example of a claim of a reasonable apprehension of bias founded upon remarks made by a judge in a social setting, see CUR24 v DPP (2012) 83 NSWLR 385.
The conduct of the trial judge involving adverse observations, in relation to one party’s case, or in relation to witnesses called by that party, especially where adverse findings are also made against that party or witnesses without proper substantiation, may lead to disqualification, see Mistral International Pty Ltd v Polstead Pty Ltd  NSWCA 321 and Damjanovic v Sharpe Hume & Co  NSWCA 407, see also Vakauta v Kelly, above, where remarks made by the trial judge critical of evidence given by the defendant’s medical witnesses, in previous cases, which were effectively revived by what was said in the reserved judgment, arose for consideration.
It does not, however, follow that trial judges must sit in stony silence, without exposing their views, at risk of being accused of bias. Genuine engagement and debate about critical issues is permissible: Re Keely; Ex p Ansett Transport Industries (Operations) Pty Ltd (1990) 64 ALJR 495 and Barbosa v Di Meglio  NSWCA 307. However, undue interference by a judge, for example, in questioning parties or witnesses, or in taking up the arguments of one party, may cross the line, as can expressions of opinion as to the likely outcome of the case prior to the conclusion of the evidence and submissions. For guidelines concerning the extent to which judicial intervention is or is not permissible, see Galea v Galea (1990) 19 NSWLR 263 at 281–282 and Royal Guardian Mortgage Management Pty Ltd v Nguyen, above.
The fact that the judge has had communication with a party, a witness or a legal representative, at or about the time of the hearing, in the absence of, and without the consent or approval of the other party, can also lead to disqualification: Re JRL Ex p CJL, above. See also Royal Guardian Mortgage Management Pty Ltd v Nguyen.
An increasingly common potential source of difficulty is the use of email to communicate with a judge’s chambers. A useful set of guidelines was given in Ken Tugrul v Tarrants Financial Consultants Pty Ltd (In liq) (No 2)  NSWSC 1971:
There should be no communication (written or oral) with a judge’s chambers in connection with any proceedings before that judge without the prior knowledge and consent of all active parties to those proceedings. Particularly in relation to written communications, given the ubiquity and speed of emails, the precise terms of any proposed communication with a judge’s chambers should be provided to the other parties for their consent.
There are four exceptions to this:
trivial matters of practice, procedure or administration (eg the start time or location of a matter, or whether the judge is robing)
ex parte matters
where the communication responds to one from the judge’s chambers or is authorised by an existing order or direction (eg for the filing of material physically or electronically with a judge’s associate), and
There are three other matters. First, any communication with a judge’s chambers which falls into any of the categories set out in sub-paragraphs  (2), (3) and (4) above should expressly bring to the addressee associate’s or tipstaff’s attention the reason for the communication being sent without another parties’ knowledge or consent. Second, where consent has been obtained, that fact should also be referred to in the communication. Third, all written communications with a judge’s chambers in relation to proceedings should always be copied to the other parties.
It is desirable for judges to have developed a clear policy with their own staff as to when emails or any other written communications received from or on behalf of litigants are shown to the judge. It is not appropriate for that decision to be left to staff without guidance from the judge: Stanizzo v Bardane  NSWSC 689 at –. See also M Groves, “Emailing judges and their staff” (2013) 37 Aust Bar Rev 69.
The fact that a judge has decided an issue in a particular way and is likely to decide it in the same way when it arises again, does not necessarily give rise to apprehended bias: Fitzgerald v Director of Public Prosecutions, above, but see also Kwan v Kang, above.
Complained of conduct should be considered in the context of the trial as a whole and the possibility of the dissipation of effect or express withdrawal of material taken into account: Jae Kyung Lee v Bob Chae-Sang Cha, above, at . Jae Kyung Lee v Bob Chae-Sang Cha contains a useful discussion of disqualification for apprehended bias.