From the European Communities Act 1972 (in force 1 January 1973) to Brexit's completion in January 2020, EU law had primacy over UK statute. Factortame (1990) saw the House of Lords disapply parts of the Merchant Shipping Act 1988 - the only true legal breach of Diceyan sovereignty in modern history.
The disagree side's answer: Parliament always retained the power to leave, and in 2016-2020 it used that power and recovered everything.
In Factortame (1990) the House of Lords disapplied parts of the Merchant Shipping Act 1988 because it conflicted with EU law - the first time in modern history a UK court refused to enforce a UK statute. From the European Communities Act 1972 taking effect in January 1973 to exit in January 2020, this was the one true legal limit Parliament has ever accepted.
Forty-seven years of integration made exit costly enough that no government attempted it until the 2016 referendum forced the question - the political constraint was real even though the legal door was always open. The cost of using a power is not the absence of the power.
The European Communities Act 1972 was repealed by the EU (Withdrawal) Act 2018, taking effect with the Withdrawal Agreement Act 2020 - the deepest constraint in the modern constitution, removed by two ordinary statutes. Dicey's second rule, demonstrated at the largest possible scale.
Even at the height of membership Parliament retained the power to legislate for exit - and in 2017-2020 it used that power. A limit Parliament can remove whenever it chooses fails Dicey's first rule test for genuine erosion.
For 47 years EU law had primacy and UK courts could disapply UK statutes - rule three genuinely broken, the only row on this grid where that is true. The agree side of the essay should be built here, and the rebuttal is one word: Factortame's arrangement is gone.
Brexit unwound the supranational arrangement completely: no EU law primacy, no disapplication power, no Luxembourg jurisdiction. Whatever else leaving cost, as a matter of legal sovereignty the recovery was total.
Real while it lasted, gone now - erosion that proved reversible is the disagree side's framing, and the strongest single sentence available for the conclusion: the one genuine breach of Diceyan sovereignty was ended by an ordinary Act of Parliament.
The Scotland Act 1998, Government of Wales Act 1998 and Northern Ireland Act 1998 created devolved legislatures with primary law-making powers. In law these are statutory grants Westminster could repeal; in politics the settlement is treated as permanent, managed by the Sewel Convention - which Miller 1 (2017) confirmed is not legally enforceable.
The Internal Market Act 2020, passed over the objection of all three devolved legislatures, is the modern proof the legal hierarchy still runs downhill from Westminster.
The Scotland Act 1998, Government of Wales Act 1998 and Northern Ireland Act 1998 are statutory grants, not transfers of sovereignty - and the Internal Market Act 2020, passed over the objection of all three devolved legislatures, proved the legal hierarchy still runs downhill from Westminster.
Repealing the Scotland Act is legally simple and politically unthinkable - the 2016 Act even declared Holyrood permanent in statute. The Sewel Convention manages the politics; Miller 1 (2017) confirmed it is a convention only, not enforceable in any court.
Every devolution statute can be amended or repealed by ordinary Act - and Westminster has legislated over devolved objection more than once, most sharply with the Internal Market Act 2020. The settlement's permanence is political fact, not legal entrenchment.
Westminster can still make any law for any part of the UK - it legislated directly for Northern Ireland during the Stormont suspensions and across all three nations in 2020. Rule one stands untouched.
No devolved legislature can override an Act of Parliament; where Holyrood legislation has exceeded its competence, the courts have struck it down, not Westminster's. The hierarchy is the opposite of erosion.
Nothing was lost in law, so nothing needed recovering - the Internal Market Act 2020 was less a recovery than a reminder of where the last word always sat.
The strongest essay line: devolution transformed the political constitution while moving legal sovereignty not an inch - the clearest illustration of the legal-political distinction the whole question turns on.
Courts can declare an Act incompatible with Convention rights (Belmarsh 2004) but cannot strike it down: a declaration has no legal force, and Parliament can legislate incompatibly if it does so in clear words. The political pressure of a declaration is real - Belmarsh produced the Prevention of Terrorism Act 2005 within months.
The Act is itself amendable: the 2022 Bill of Rights Bill attempted replacement, and the Safety of Rwanda Act 2024 disapplied parts of it.
Section 4 of the HRA lets courts declare a statute incompatible with Convention rights - Belmarsh (2004) is the landmark use - but a declaration has no legal force: the Act stands until Parliament chooses otherwise. The design preserved sovereignty deliberately.
The political pressure of a declaration is real: Belmarsh produced the Prevention of Terrorism Act 2005 within months. But pressure Parliament can resist (prisoner voting after Hirst) is influence, not a limit.
The HRA is amendable and disappliable by ordinary statute - the 2022 Bill of Rights Bill attempted wholesale replacement, and the Safety of Rwanda Act 2024 disapplied parts of it for removal cases. The reversibility is not theoretical; it has happened.
The codification grid runs the same episodes through the opposite question: whether rights this easy to unpick should be entrenched.
Parliament can legislate incompatibly with Convention rights provided it does so in clear words - and in 2024 it did exactly that, declaring Rwanda safe by statute against a Supreme Court finding.
No court can strike down an Act under the HRA - the contrast with the US Supreme Court is the standard comparative point, and the reason UK rights essays end at Parliament rather than in court.
Nothing was lost in law - though the 2024 disapplication showed Parliament actively reasserting the hierarchy when it judged the courts had pressed too far.
Influence, not erosion: the HRA changed how Parliament legislates and how ministers behave, while leaving Parliament able to override the whole apparatus by simple majority - which, in 2024, it did.
Referendums are advisory in law - even the 2016 EU referendum did not legally bind Parliament, as Miller 1 confirmed by requiring an Act to trigger Article 50. But no Parliament dared ignore the result, and no major constitutional change now happens without one.
This is the agree side's strongest ground: on the biggest questions, the political location of sovereignty has arguably moved from Parliament to the electorate.
Referendums are advisory in law: even the 2016 EU referendum did not legally bind Parliament, as Miller 1 confirmed by requiring an Act before Article 50 could be triggered. Each referendum exists only because an Act of Parliament created it.
No Parliament dared ignore the 2016 result, a Commons with a large Remain majority legislated for Brexit, and no major constitutional change now happens without a referendum - 1975, 1997-98, 2011, 2014, 2016. The political binding is as strong as any legal rule.
Parliament sets every referendum's question, franchise and timing by Act, and could in principle legislate against a result - the constraint is political consequence, not law.
Parliament legislated for Brexit itself - the EU (Notification of Withdrawal) Act 2017 and the Withdrawal Acts were Parliament exercising rule one, not surrendering it. Sovereignty used at the electorate's instruction is still sovereignty.
No referendum result overrides an Act - the 2016 result changed nothing in law until Parliament legislated. The formal hierarchy held even in the most politically binding vote in modern history.
Nothing was lost in law to recover - but note the ratchet: once a question has been put to the people, taking it back into Parliament's hands alone may no longer be politically possible.
The one arguably real erosion on the grid: on the biggest constitutional questions, the political location of sovereignty has moved towards the electorate - popular sovereignty operating inside a legally Diceyan system. The strongest agree paragraph available, provided it is framed as political, not legal.
The Miller rulings policed prerogative power, not statute: Miller 1 required an Act to trigger Article 50 (protecting Parliament's role), Miller 2 protected Parliament's right to sit. The Court has never struck down an Act of Parliament and cannot.
The Safety of Rwanda Act 2024 completed the picture: when Parliament answered the Court by statute, the Court accepted it.
Judicial review polices ministers' use of power, not Parliament's statutes: Miller 1 (2017) controlled the prerogative, Miller 2 (2019) quashed a prorogation - neither touched an Act. The courts' strongest modern rulings were about protecting Parliament, not limiting it.
Governments legislate and act in anticipation of review - the Rwanda policy was redesigned around the courts at every step. Anticipatory compliance is a real constraint on the executive; it is not a constraint on Parliament.
Parliament can and does legislate to reverse judicial outcomes - the Safety of Rwanda Act 2024 answered the Supreme Court's November 2023 ruling by statute within months, and the Court accepted it.
Miller 1 demanded more parliamentary law-making, not less: the ruling's effect was that only an Act could trigger Article 50. The supposed judicial threat to sovereignty keeps ruling in sovereignty's favour.
No UK court has ever struck down an Act of Parliament, and the Supreme Court's acceptance of the Rwanda Act 2024 showed the hierarchy operating under maximum strain - the court overruled, the statute stood.
The Rwanda sequence is the last word in action: ruling (November 2023), statute (2024), acceptance. Whatever judicial power grew in the Miller era, the 2024 episode measured its ceiling.
The courts have served sovereignty more than limited it - both Millers protected Parliament's role against the executive, and the one direct collision ended with Parliament's statute standing. File judicial review under executive constraint, not sovereignty erosion.
The EU (Withdrawal Agreement) Act 2020 completed Brexit and unwound Factortame's supranational arrangement. The Internal Market Act 2020 legislated over the objection of all three devolved nations. The Safety of Rwanda Act 2024 overrode a Supreme Court ruling by statute.
Taken together, 2020-24 is the strongest modern evidence that parliamentary sovereignty is not merely intact but operational at full force.
The 2020-24 statutes removed legal constraints rather than adding them: the Withdrawal Agreement Act 2020 ended EU law primacy, and the Safety of Rwanda Act 2024 disapplied parts of the HRA for one policy area. The era's legal direction of travel was all one way.
Westminster legislated over the objection of all three devolved legislatures (Internal Market Act 2020) and over a unanimous Supreme Court ruling of November 2023 (Safety of Rwanda Act 2024) - political constraints that bind other governments simply did not bind this Parliament.
Every instrument of the era is ordinary statute - including the Rwanda Act itself, repealed or replaced as easily as it was passed. The era proves reversibility in both directions.
Parliament made and unmade the biggest laws of the age - exiting a 47-year supranational order, restructuring the internal market, overriding a court ruling. Rule one has rarely been exercised so visibly.
The Supreme Court accepted the Safety of Rwanda Act without push-back - no body overrode an Act; an Act overrode a ruling. Rule three ended the era stronger than it began it.
This row is the recovery: Factortame's arrangement unwound, the devolved objections overridden, the Court answered by statute. The change-over-time arc examiners reward runs 1973 (pooled) to 1990 (Factortame) to 2020 (recovered) to 2024 (asserted).
The strongest evidence on the grid that sovereignty is intact - arguably stronger than ever. The counterweight for a balanced conclusion is the referendum row: legally supreme, Parliament now acts under instruction from the electorate on the biggest questions.