Natural justice
In English law, natural justice is technical terminology for the rule against bias (nemo iudex in causa sua) and the right to a fair hearing (audi alteram partem). While the term natural justice is often retained as a general concept, it has largely been replaced and extended by the general "duty to act fairly".
Not to be confused with Natural law.
The basis for the rule against bias is the need to maintain public confidence in the legal system. Bias can take the form of actual bias, imputed bias, or apparent bias. Actual bias is very difficult to prove in practice whereas imputed bias, once shown, will result in a decision being void without the need for any investigation into the likelihood or suspicion of bias. Cases from different jurisdictions currently apply two tests for apparent bias: the "reasonable suspicion of bias" test and the "real likelihood of bias" test. One view that has been taken is that the differences between these two tests are largely semantic and that they operate similarly.
The right to a fair hearing requires that individuals should not be penalized by decisions affecting their rights or legitimate expectations unless they have been given prior notice of the case, a fair opportunity to answer it, and the opportunity to present their own case. The mere fact that a decision affects rights or interests is sufficient to subject the decision to the procedures required by natural justice. In Europe, the right to a fair hearing is guaranteed by Article 6(1) of the European Convention on Human Rights, which is said to complement the common law rather than replace it.
Rule against bias[edit]
In general[edit]
People are barred from deciding any case in which bias exists or bias may fairly be suspected. This principle embodies the basic concept of impartiality,[11] and applies to courts of law, tribunals, arbitrators and all those having the duty to act judicially.[12] A public authority has a duty to act judicially whenever it makes decisions that affect people's rights or interests, and not only when it applies some judicial-type procedure in arriving at decisions.[13]
The basis on which impartiality operates is the need to maintain public confidence in the legal system. The erosion of public confidence undermines the nobility of the legal system and leads to ensuing chaos.[14] The essence of the need for impartiality was observed by Lord Denning, the Master of the Rolls, in Metropolitan Properties Co (FGC) Ltd v Lannon (1968):[15] "Justice must be rooted in confidence and confidence is destroyed when right-minded people go away thinking: 'The judge was biased.'"[15]: 599
Public confidence as the basis for the rule against bias is also embodied in the often-quoted words of Lord Hewart, the Lord Chief Justice of England and Wales, that "[i]t is not merely of some importance, but of fundamental importance that justice should not only be done, but should manifestly be seen to be done".[16]