"We accept that there is jurisdiction for a Tribunal to discontinue a hearing and order a re-hearing (C harman v Palmers Scaffolding Ltd[1970] ICR 335 and Automobile Proprietary Ltd v Healy[1979] ICR 809 ). But those cases also make it clear that that power should be exercised most sparingly and only for very good reason; a bare allegation of bias is not sufficient. We take it to be axiomatic that justice before a Tribunal must not only be done but also be manifestly seen to be done. That applies as much in our view to a Tribunal such as the Industrial Tribunal as it does to a formal court of law. Not only must there be no bias on the part of the Tribunal but also the Tribunal must not give the appearance of bias. Where there is an allegation of bias based on the conduct of one or more members of a Tribunal at a hearing, the test is, in our view, an objective one: would the reasonable observer present at the hearing, not being a party, or associated with a party, to the proceedings but knowing the issues, reasonably gain the impression of bias. That impression may be given by the appearance of a closed mind against a party on a matter which calls for decision by the Tribunal when that party has not yet presented all his evidence relevant to the point or had the opportunity of addressing the Tribunal on that evidence."
"... The test to be applied in all cases of apparent bias was the same, whether concerning justices, members of inferior tribunals, arbitrators or jurors, and in cases involving jurors, whether being applied by the judge during the trial or by the Court of Appeal when considering the matter on appeal, namely, whether, in all the circumstances of the case, there appeared to be a real danger of bias, concerning the member of the tribunal in question so that justice required that the decision should not stand. ..."