Three former MPs and a peer, charged with false accounting over their parliamentary expenses claims, argued that article 9 of the Bill of Rights and exclusive cognisance protected them from prosecution. The Supreme Court unanimously held that the claims were not proceedings in Parliament and that the courts had jurisdiction. The case defines the narrow scope of article 9.

Pickin is the leading modern authority that the courts will not look behind an Act of Parliament to investigate the way it was passed. A landowner alleged that the Railways Board had fraudulently misled Parliament, but the House of Lords held that the courts could not inquire into the proceedings by which a private Act was enacted. It is cited as an expression of the enrolled Act rule and parliamentary sovereignty.

Opponents of the ban on fox hunting argued that the Hunting Act 2004 was invalid because the Parliament Act 1949, under which it was passed without the consent of the Lords, was itself invalid. The House of Lords held that the 1949 Act was valid. Several Lords also commented on the limits of parliamentary sovereignty.

Spanish-owned fishing companies challenged Part II of the Merchant Shipping Act 1988 as contrary to Community law and sought interim relief suspending it. The House of Lords held that English law gave the courts no power to grant interim relief against the Crown or to suspend an Act, but referred to the European Court the question whether Community law required it. This is the first stage of the Factortame litigation on the status of Community law against later Acts.

The Prime Minister advised the Queen to prorogue Parliament for about five weeks shortly before the date set for the United Kingdom to leave the European Union. The Supreme Court held that the legality of the advice was justiciable and that the advice was unlawful because it frustrated the ability of Parliament to carry out its functions without reasonable justification. The prorogation was therefore of no effect.

After Rhodesia's unilateral declaration of independence, Westminster remained sovereign and the detention was unlawful.

A minister's statutory discretion must be used to promote the policy of the Act

Privacy International challenged a ruling of the Investigatory Powers Tribunal on the scope of intelligence service warrants, and the question was whether section 67(8) of the Regulation of Investigatory Powers Act 2000 excluded judicial review. By a majority of four to three the Supreme Court held that it did not, so that the High Court could review the Tribunal's decisions for error of law. It is the leading modern case on ouster clauses and the constitutional role of judicial review.

A blanket policy infringing legal privilege was unlawful at common law and under Article 8.

Landowners relied on a provision in a 1919 Act that stated that inconsistent provisions in later Acts would have no effect, but a later housing statute provided a different method of compensation. The Court of Appeal held that the later Act prevailed, since Parliament cannot bind itself as to the form of future legislation. It is the classic authority for the doctrine of implied repeal.

Orders in Council barring the Chagossians' return were upheld by a bare majority.

The Crown cannot rely on the prerogative where statute has covered the same ground.

Fairness required the Home Secretary to disclose and explain his life sentence tariff decisions.

A public authority may adopt a policy but must listen to arguments for an exception.

Supreme Court declined a declaration that the ban on assisted suicide breaches Article 8.

Prerogative powers are reviewable in principle, but national security defeated the claim.