The Doctrine of Legitimate Expectation is a principle of administrative law that holds that a person has the right to expect that a public authority will act in a particular way if it has given a representation, assurance or indication that it will do so. This principle is based on the idea that a person should not be prejudiced by a change in the position of a public authority if that person has relied on the representation or assurance given by the authority.

The Doctrine of Legitimate Expectation has its roots in the principle of fairness and natural justice, which are fundamental to the functioning of the administrative law system. The principle of fairness requires that public authorities should act in a way that is fair and reasonable, and that they should not act in a way that would be unjust or oppressive to individuals. The principle of natural justice requires that public authorities should provide a person with an opportunity to be heard before making a decision that affects their interests.

The Doctrine of Legitimate Expectation has been developed in several landmark cases in the UK and India. In the UK, the case of Council of Civil Service Unions v. Minister for the Civil Service (1985) established the principle that a public authority is under a duty to act in accordance with its own representations, unless there is a good reason not to do so. In India, the case of Union of India v. Hindustan Development Corporation (1991) established the principle that a person has a legitimate expectation that a public authority will act in accordance with its own representations, unless there is a good reason not to do so.

The Doctrine of Legitimate Expectation has been applied in a wide range of cases, including cases involving the granting of licenses and permits, the award of contracts, the provision of benefits, the exercise of discretion, and the decision-making processes of public authorities. The principle has been used to protect the rights of individuals and to ensure that public authorities are held accountable for their actions.

The Doctrine of Legitimate Expectation applies to all public authorities, including government departments, local authorities, and regulatory bodies. The principle requires that public authorities should act in a way that is consistent with their representations and assurances, and that they should not act in a way that would be unjust or oppressive to individuals.

The Doctrine of Legitimate Expectation has several important implications for public authorities. Firstly, it requires public authorities to be transparent in their decision-making processes and to provide individuals with clear and accurate information about their policies and procedures. Secondly, it requires public authorities to be consistent in their dealings with individuals, and to avoid acting in a way that would be inconsistent with their representations or assurances. Finally, it requires public authorities to be fair and reasonable in their dealings with individuals, and to ensure that they are not acting in a way that would be unjust or oppressive.

Some landmark judgements on the Doctrine of Legitimate Expectation in India include:

1. Union of India v. Hindustan Development Corporation (1991): This case established the principle that a person has a legitimate expectation that a public authority will act in accordance with its own representations, unless there is a good reason not to do so.
2. Central Inland Water Transport Corporation Limited v. Brojo Nath Ganguly (1986): This case established the principle that a person has a legitimate expectation that a public authority will not act in a way that would be inconsistent with its representations or assurances.
3. Union of India v. Tulsiram Patel (1987): This case established the principle that a public authority is under a duty to act in accordance with its own representations, unless there is a good reason not to do so.
4. Ajay Hasia v. Khalid Mujib Sehravardi (1981): This case established the principle that a person has a legitimate expectation that a public authority will act in accordance with its own policies and procedures.
5. Oil and Natural Gas Corporation Limited v. Saw Pipes Limited (2003): This case established the principle that a public authority is under a duty to act in accordance with its own representations, unless there is a good reason not to do so.

These landmark judgements have helped to establish the Doctrine of Legitimate Expectation as an important principle of administrative law in India, and have provided guidance for public authorities and individuals on the application of this principle in practice.

In conclusion, the Doctrine of Legitimate Expectation is an important principle of administrative law that helps to ensure that public authorities are held accountable for their actions and that individuals are protected from unjust or oppressive treatment by the state. The principle is based on the idea that a person should not be prejudiced by a change in the position of a public authority if they have relied on the representation or assurance given by the authority, and that public authorities should act in a way that is fair, reasonable, and consistent. The Doctrine of Legitimate Expectation is an essential component of the administrative law system, and it plays an important role in ensuring that public authorities are held accountable for their actions and that individuals are protected from unjust or oppressive treatment by the state.