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

The Home Secretary attempted to introduce a tariff scheme for criminal injuries compensation without implementing the statutory scheme Parliament had enacted. The House of Lords ruled this was an abuse of power, as ministers cannot use prerogative powers to frustrate the will of Parliament.

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 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.

Derek Bentley was hanged in 1953 for murder. His family sought judicial review of the Home Secretary's refusal to grant a posthumous pardon. The Court of Appeal held that while the prerogative of mercy is not generally justiciable, the court could grant declaratory relief where the Home Secretary had failed to recognize the scope of the prerogative or applied wrong principles.

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.

Ratification of Maastricht Treaty a non-justiciable matter of high policy.

The Attorney General sought to prevent publication of 'Spycatcher', memoirs of former MI5 officer Peter Wright, on grounds of breach of confidence. The House of Lords held that once information had entered the public domain through overseas publication, there was no further basis for restraining publication in England, as the confidentiality had been destroyed.

The House of Lords set aside its earlier decision due to Lord Hoffmann's undisclosed connection to Amnesty International, establishing strict rules about judicial bias and the appearance of justice.

House of Lords rules prerogative powers subject to judicial review

House of Lords clarifies crucial distinction between trusts and powers

Crown liable to compensate for property destroyed under wartime prerogative powers.

Ministers cannot adopt blanket policies that fetter discretionary statutory powers.

Imperfect gifts cannot be rescued by implying declaration of trust

Ministers cannot refuse to exercise statutory powers for improper purposes

Novus actus interveniens breaks chain of causation where negligent act is not foreseeable consequence

Court establishes certainty requirement for charitable trusts and cy-près doctrine

Threat of strike action constituting intimidation is actionable tort even without actual violence

Courts cannot question the validity of Acts of Parliament once properly enacted.

EU law supremacy requires domestic courts to disapply conflicting national legislation.

House of Lords confirms EU law supremacy over UK Acts of Parliament

Courts cannot question Parliament's internal procedures when examining the validity of Acts.

Established the four heads of charity: religion, education, relief of poverty, other purposes beneficial to community.

Crown and ministers can be held in contempt of court