The doctrine of legitimate expectation in Singapore protects both procedural and substantive rights. In administrative law, a legitimate expectation generally arises when there has been a representation of a certain outcome by the public authorities to an individual. To derogate from the representation may amount to an abuse of power or unfairness. The doctrine of legitimate expectation as a ground to quash decisions of public authorities has been firmly established by the English courts. Thus, where a public authority has made a representation to an individual who would be affected by a decision by the authority, the individual has a legitimate expectation to have his or her views heard before the decision is taken. Alternatively, an individual may also have a legitimate expectation to a substantive right. The recognition of substantive legitimate expectations is somewhat controversial as it requires a balancing of the requirements of fairness against the reasons for any change in the authority's policy. This suggests the adoption of a free-standing proportionality approach, which has been said not to apply in administrative law.
The procedural dimension of the doctrine of legitimate expectation has been recognized by Singapore courts and, since 2013, the substantive form of the doctrine as well. However, whether the courts will adopt the UK approach with regard to measuring legitimate expectation with the ruler of proportionality remains an open question.