15 named examples with their significance, drawn from the Panther database. Read them, then test yourself.
In test mode, tap an example to reveal why it matters.
The examples
Brexit Withdrawal Agreement Defeat (January 2019)(2019)(tap to reveal)- May's deal defeated 432-202: largest government defeat in history. 118 Conservative rebels. Shows backbenchers can defeat government even with large majority. Key example for Commons effectiveness questions.
Brexit: Parliament, People, and Democracy (2016-20)(2016)(tap to reveal)- 52-48% referendum result. Three meaningful vote defeats. Prorogation attempt. Shows tension between direct and representative democracy. Biggest constitutional crisis in modern British politics.
Cameron's Brexit Referendum (2016): The Elastic Model of PM Power in Practice(2016)(tap to reveal)- Cameron included the referendum pledge in the 2015 Conservative manifesto, expecting to win as he had won a similar AV referendum pledge in 2011. He negotiated a renegotiation deal with the EU (February 2016) and campaigned for Remain. On 24 June 2016 the Leave side won 51.9% to 48.1%. Cameron resigned the same morning. His successor Theresa May faced three years of parliamentary gridlock implementing the result.
Caroline Spellman: Burkean Trusteeship and Brexit Vote (2019)(2019)(tap to reveal)- Caroline Spellman voted against Brexit in 2019 Commons votes despite her constituency having backed Leave in 2016. She exercised her own judgement as a representative rather than following constituency opinion.
EU Referendum 2016: Scotland 62% Remain, England Majority Leave - Constitutional Tension(2022)(tap to reveal)- The 2016 EU referendum produced a UK-wide result of 52% Leave, but Scotland voted 62% Remain (67% turnout) and Northern Ireland voted 55.8% Remain. This created an immediate constitutional tension: Scotland had voted decisively for a policy overturned by English votes. Nicola Sturgeon said Scotland had 'spoken decisively' for Remain and called for a second independence referendum (indyref2). The Scottish Government published a paper on holding a second referendum in 2017. Legal challenge ultimately led to the Supreme Court's 2022 ruling that Holyrood could not hold an independence referendum without Westminster consent. Northern Ireland's Remain vote created the 'Irish Border problem' that dominated subsequent Brexit negotiations.
Northern Ireland Protocol Bill and Windsor Framework (2023)(2023)(tap to reveal)- The Truss government introduced the Northern Ireland Protocol Bill in 2022, attempting to unilaterally override parts of the NI Protocol that regulated trade between Great Britain and Northern Ireland post-Brexit. The Sunak government subsequently negotiated the Windsor Framework (2023) with the EU as an alternative to unilateral action. The Framework modified the Protocol through negotiation rather than unilateral legislation.
R (HS2 Action Alliance Ltd) v Secretary of State for Transport (2014)(2014)(tap to reveal)- In HS2 (2014), the Supreme Court considered whether the government's decision to build the HS2 railway interfered with Parliamentary privilege. Lord Neuberger and Lord Mance suggested that certain constitutional principles - specifically Article 9 of the Bill of Rights protecting freedom of speech in Parliament - might not be subject to EU law supremacy, hinting at constitutional limits to EU power.
R (Miller) v Secretary of State for Exiting the EU (2017) - "Miller I"(2017)(tap to reveal)- In Miller I (2017), the Supreme Court ruled 8-3 that the government could not use the royal prerogative to trigger Article 50 (beginning the Brexit process) without Parliamentary authorization. The decision held that because triggering Article 50 would remove rights granted to UK citizens by EU law, an Act of Parliament was necessary. This led to the EU (Notification of Withdrawal) Act 2017.
R (Miller) v The Prime Minister (2019) - "Miller II" / Cherry(2019)(tap to reveal)- In Miller II (2019), the Supreme Court unanimously ruled 11-0 that Prime Minister Johnson's prorogation (suspension) of Parliament for five weeks in September 2019 was unlawful. The government claimed it needed to prorogue Parliament to prepare a new legislative agenda, but the court held that the true purpose was to limit Parliamentary scrutiny of the Brexit process, making it a misuse of the prerogative power.
R v Secretary of State for Transport, ex parte Factortame (1990)(1990)(tap to reveal)- In Factortame (1990), the House of Lords disapplied part of the Merchant Shipping Act 1988 following an ECJ ruling that it breached EU law. The Act had required fishing vessels to be majority-British owned, disadvantaging Spanish fishing company Factortame Ltd. It was the first modern instance of a UK court setting aside an Act of Parliament, establishing the supremacy of EU law over conflicting UK statutes.
Retained EU Law Act 2023(2023)(tap to reveal)- The Retained EU Law Act 2023 allowed ministers to revoke or replace EU-derived laws now part of UK law by statutory instrument. It originally included a sunset clause removing all retained EU law by 31 December 2023, but this was softened to a schedule-based approach following pressure from the House of Lords during passage.
Retained EU Law Act 2023: Henry VIII Powers and Parliamentary Pushback(2023)(tap to reveal)- Original bill gave ministers power to revoke all EU-derived law by SI; scope narrowed after parliamentary opposition; Lords defeated government multiple times
The Sewel Convention and Devolution (1998-present)(1998-present)(tap to reveal)- Sewel Convention: Westminster will not normally legislate on devolved matters without Holyrood consent. Given statutory footing in Scotland Act 2016. Overridden during Brexit 2017-20 when Westminster legislated on devolved matters without Scottish Parliament consent despite 9-0 vote against.
Thoburn v Sunderland City Council (2002) - 'Metric Martyrs'(2002)(tap to reveal)- In Thoburn v Sunderland (2002), the High Court established the concept of "constitutional statutes" - Acts such as Magna Carta, the Bill of Rights, and the European Communities Act 1972 that form the constitutional framework of the UK. The court held that these statutes cannot be impliedly repealed by later legislation; only express words will suffice.
UK-EU Reset Deal 2025: Sanitary, Defence, and Youth Mobility(2025)(tap to reveal)- The May 2025 UK-EU Reset agreement established new cooperation on sanitary food rules (SPS), defence and security, and a youth mobility scheme - the most significant post-Brexit warming.