Decisions made by public authorities may be challenged on the grounds that they are unreasonable.
The test that the Court applies to decide whether a decision is reasonable, and how intensely or closely it reviews a decision, will vary according to the circumstances and context of each case. However, the test that is applied most often is whether the public authority’s decision is within the “range of reasonable” decisions that a public authority could have made in the circumstances.
In some cases, particularly those involving political judgment, there will be a high threshold and it will be difficult for the claimant to show that the decision is unreasonable.
In other cases, particularly those involving a person’s rights or constitutional principles, the threshold will be lower and the Court will give more careful scrutiny to the decision.