Relevant and irrelevant considerations in Singapore administrative law
The failure of a public authority to take into account relevant considerations and the taking of irrelevant ones into account are grounds of judicial review in Singapore administrative law. They are regarded as forms of illegality. If, in the exercise of its discretion on a public duty, an authority takes into account considerations which the courts consider not to be proper, then in the eyes of the law it has not exercised its discretion legally. On the other hand, considerations that are relevant to a public authority's decision are of two kinds: there are mandatory relevant considerations (that is, considerations that the statute empowering the authority expressly or impliedly identifies as those that must be taken into account), and discretionary relevant considerations (those which the authority may take into account if it regards them as appropriate). If a decision-maker has determined that a particular consideration is relevant to its decision, it is entitled to attribute to it whatever weight it thinks fit, and the courts will not interfere unless it has acted in a Wednesbury-unreasonable manner.