Which principle states that laws must be applied clearly and predictably in the UK justice system?

The principle of legal certainty is fundamental in ensuring that laws are applied in a clear and predictable manner within the UK justice system. This concept allows individuals to understand what the law is and how it applies to their actions, promoting fairness and stability. Legal certainty ensures that laws are written in a way that can be easily understood and are consistently enforced, which helps people know what to expect from the legal system and what the consequences of their actions will be.

In contrast, the other principles, while important, do not specifically emphasize the clarity and predictability of laws. Equality before the law pertains to the idea that all individuals should be treated the same under the law, regardless of their status. Due legal process refers to the requirement that legal proceedings be conducted fairly and in accordance with established rules. Non-retrospective law focuses on the principle that laws should not be applied to actions that occurred before the laws were enacted. While all these principles contribute to a just legal system, legal certainty specifically addresses the need for laws to be understandable and reliably applied.