Wednesbury unreasonableness in Singapore law

Wednesbury unreasonableness is a ground of judicial review in Singapore administrative law. A governmental decision that is Wednesbury-unreasonable may be quashed by the High Court. This type of unreasonableness of public body decisions was laid down in the English case of Associated Provincial Picture Houses v. Wednesbury Corporation (1947), where it was said that a public authority acts unreasonably when a decision it makes is "so absurd that no sensible person could ever dream that it lay within the powers of the authority".

Wednesbury unreasonableness was subsequently equated with irrationality by the House of Lords in Council of Civil Service Unions v. Minister for the Civil Service (the GCHQ case, 1983). These cases have been applied numerous times in Singapore, though in some decisions it is not very clear whether the courts have applied such a stringent standard.

In the UK, courts have applied varying standards of scrutiny when assessing whether a governmental decision is Wednesbury-unreasonable, depending on the subject matter and general context of the case. There do not appear to be any Singapore cases adopting an "anxious scrutiny" standard. On the other hand, a few cases can be said to have applied a "light touch" standard where questions of public order and security have arisen. There are suggestions in the UK that a doctrine of proportionality should supplant or be merged into the concept of Wednesbury unreasonableness; thus far, such an approach has not been taken up in Singapore. It is said that in holding that a decision is disproportionate, there is a higher danger that the court might be substituting its view for the decision-maker's.