When Parliament provides a statutory scheme for government action, ministers cannot bypass it by relying on broader prerogative powers.

House of Lords held that local authorities must act reasonably and cannot ignore their fiduciary duty to ratepayers when setting wages, establishing early principles of Wednesbury unreasonableness.

Public authorities may owe duties of care when exercising statutory functions.

The Case of Proclamations established that the King cannot create new law or change existing law through royal proclamation alone. This landmark case confirmed that royal prerogative powers are limited and cannot override statute or common law without parliamentary consent.

This landmark case established that bodies exercising public functions can be subject to judicial review even if they lack statutory authority or government appointment. The Court of Appeal held that the Panel on Takeovers and Mergers, despite being a self-regulating private body, could be judicially reviewed because it exercised public law functions.

UK courts can disapply conflicting domestic legislation and grant interim relief against the Crown when EU law supremacy is at stake.

Educational trusts must benefit sufficient section of public, not just company employees' relatives.

Police services beyond public duty constitute valid consideration for contractual obligations.

This case established the famous 'Wednesbury unreasonableness' test for judicial review of administrative decisions. It set the standard that courts can only overturn administrative decisions if they are so unreasonable that no reasonable authority could have reached them.

Government agents broke into John Entick's house and seized his papers under a warrant issued by the Secretary of State. The court ruled this was unlawful, establishing that government power must have legal authority and that every invasion of private property must be justified by law.

This case established when prisoners have a right to an oral hearing before the Parole Board under common law fairness principles and Article 5(4) ECHR. The Supreme Court clarified that procedural fairness requires consideration of individual circumstances, not blanket policies denying hearings.

This early case established that the Crown cannot create new crimes or alter the law by proclamation alone, requiring parliamentary consent for changes to the common law.

House of Lords held that GLC's 'Fares Fair' policy of subsidising public transport through supplementary rates was ultra vires as it breached fiduciary duty to ratepayers.

Certain statutes have constitutional status and cannot be impliedly repealed.

Government prohibition can frustrate contracts, with losses apportioned under Law Reform Act.

The House of Lords established that courts cannot inquire into Parliament's internal procedures when passing Acts, reinforcing the enrolled bill rule and parliamentary sovereignty.

The House of Lords established the fundamental principle that judges must not have any financial interest in cases they decide, creating the rule against pecuniary bias.

Court of Common Pleas established that natural justice requires a hearing before a person is deprived of their property or rights, even where not expressly required by statute.

Ministers cannot adopt blanket policies that fetter discretionary statutory powers.

Court of Appeal established the fundamental principle that justice must not only be done but must manifestly be seen to be done.

The Court of Appeal held that later Acts of Parliament impliedly repeal earlier conflicting provisions, establishing the doctrine of implied repeal in parliamentary sovereignty.

EU directives may be enforced against state entities and emanations of the state.

John MacCormick challenged the Queen's title as 'Elizabeth II' in Scotland, arguing Elizabeth I never reigned there. The Court of Session held that while courts cannot question the validity of Acts of Parliament, certain constitutional arrangements may be justiciable, though this particular claim failed.

Four prisoners challenged decisions of a prison board of visitors by writ and originating summons rather than judicial review. The House of Lords held this was an abuse of process. Where the sole aim is to challenge a public law decision, judicial review is the exclusive procedure, protecting public bodies from unmeritorious claims.

The Court of Appeal held that a health authority's decision to close a NHS facility and relocate disabled residents breached legitimate expectations created by previous promises. This landmark case established important principles about when public bodies can resile from commitments made to individuals.

Cannot take benefit of deed without accepting corresponding burdens - mutual benefit and burden

The claimant sought judicial review claiming legitimate expectation based on statements in a White Paper regarding assisted places at independent schools. The Court of Appeal held that to establish legitimate expectation, there must be a clear and unambiguous representation made to a specific individual or group, not general policy statements in government documents.

Trust for company employees' children fails public benefit test for charity

The GCHQ case established that government prerogative powers are subject to judicial review, but national security concerns can exclude procedural fairness requirements. This landmark decision expanded judicial oversight of executive power while recognizing legitimate security limitations.

Ministers cannot use prerogative powers to frustrate Parliament's statutory scheme

UK courts cannot review the validity of Acts of Parliament, even when they allegedly breach international obligations or affect other countries' constitutional arrangements.

Liverpool Corporation increased the number of taxi licences without consulting existing licence holders who had relied on assurances that no increase would occur. The Court of Appeal held that public authorities must act fairly and consult affected parties before changing established policies, even absent a legal duty to do so.

The National Federation of Self-Employed sought judicial review of the Inland Revenue's decision to grant amnesty to casual workers in the Fleet Street printing industry. The House of Lords held the Federation lacked sufficient interest (standing) to challenge the Revenue's tax enforcement decisions. The court established that standing must be assessed in relation to the specific legal duty allegedly breached.

Ministers cannot refuse to exercise statutory powers for improper purposes

Hong Kong immigration officers made representations to illegal immigrants from Macau that each case would be considered individually before removal. The Privy Council held that such representations gave rise to a legitimate expectation of a hearing, even though no legal right to one existed. This established that procedural fairness may be required where clear undertakings are given by public authorities.

State liability extends to legislative acts where breach manifestly and gravely disregards EU law.

Administrative bodies may adopt policies but must consider exceptional cases

Restraint of trade covenants must be reasonable between parties and serve public interest.