Natural justice

Natural justice is a technical term in English law that refers to two fundamental procedural rights: the rule against bias, known as nemo iudex in causa sua (no man a judge in his own cause), and the right to a fair hearing, known as audi alteram partem (hear the other side). While the term is often retained as a general concept, it has largely been replaced and extended by the broader "duty to act fairly" in jurisdictions such as Australia and the United Kingdom. The concept is similar to the American ideas of fair procedure and procedural due process. However, it is distinct from the philosophical notions of natural law, the ideal patterns of society envisioned by medieval thinkers, or the natural rights philosophy of the 18th century.

In general

The rule against bias is rooted in the need to maintain public confidence in the legal system. Bias can be actual, imputed, or apparent. Actual bias is difficult to prove, while imputed bias, once shown, voids a decision without further investigation.

For apparent bias, two tests are applied across different jurisdictions: the "reasonable suspicion of bias" test and the "real likelihood of bias" test, though the differences between them are often considered semantic. The right to a fair hearing requires that individuals receive prior notice of a case, a fair opportunity to respond, and the chance to present their own case before decisions affecting their rights or legitimate expectations are made. The mere fact that a decision impacts rights or interests is enough to trigger these procedural requirements. In Europe, this right is guaranteed by Article 6(1) of the European Convention on Human Rights, which complements rather than replaces the common law.

Background

The specific requirements of natural justice or the duty to act fairly depend on context, as established in cases like Baker v Canada (1999), where the Supreme Court of Canada listed factors such as the nature of the decision, the statutory scheme, the importance of the decision to the individual, and their legitimate expectations. Public authorities making legislative and general decisions generally do not have a duty to act fairly, while those making administrative and specific decisions do. No duty exists in master-servant relationships or where an individual holds office at pleasure, but it does apply where removal is only for cause.