Edexcel A-Level Politics 9PL0 · Paper 2 UK Government · Content area 1 of 6

1. The constitution

1.1 the nature and sources of the UK constitution · 1.2 the core principles · 1.3 the uncodified constitution: strengths and weaknesses · 1.4 should the UK adopt a codified constitution.

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1.1 The nature and sources of the UK constitution Done

Essential Where the constitution comes from when there is no single document: the five sources, and the three features that define it - uncodified, unentrenched and unitary.

The specification

1.1The nature and sources of the UK constitution

The UK constitution is uncodified - there is no single document - and unentrenched, so an ordinary Act of Parliament can change it. I can do this

Its five sources are statute law, common law, conventions, works of authority and treaties. I can do this

Statute law is the most important source because of parliamentary sovereignty; conventions are binding by practice but not by law. I can do this

Wording above follows the Pearson specification. Tick a line only when you could answer on it without notes.

Past questions - how it has been examined

Directly: 2025 Q1a (the UK constitution, source) and 2020 Q1b (the UK constitution, source) both reward a clear grasp of the sources.
As the framing: Sample Q1a (federalism as a logical next step, source) turns on the unitary nature of the present constitution.

Pattern. Every constitution question rests on the sources. Learn the five sources and the three features (uncodified, unentrenched, unitary) as the base layer for the whole area.

What examiners reward and penalise

Stronger answers use the sources as evidence - naming a statute, a convention and a case - rather than listing the five sources as a definition.
Weaker answers confuse uncodified with unwritten; much of the constitution is written down (statutes and cases), it is simply not gathered into one codified document.

One way to get high marks

Credited: uncodified means no single document, not unwritten; statute, common law and treaties are all written, while conventions are the genuinely unwritten part.
Rewarded evidence: the Human Rights Act 1998 and Constitutional Reform Act 2005 (statute), the Salisbury and Sewel conventions (conventions), Dicey and Bagehot (works of authority), and the European Communities Act 1972 (treaty given domestic force).
Level 5 over Level 4: shows how the sources fit together - statute on top because Parliament is sovereign, conventions filling the gaps - rather than describing each in isolation.

The 30-mark questions. Marks split 10/10/10 across AO1 (knowledge), AO2 (analysis) and AO3 (evaluation), so an answer that describes without judging throws away a third of the marks. Examiners reward a clear and consistent line of argument: decide your view before you write, argue it in every paragraph, weigh the counter-argument as you go, and reach a substantiated judgement. A one-sided essay is capped at Level 2 however much it knows, and you should structure by theme rather than as a list of examples. On the Question 1 source question you must use the source - compare the two opposing views it contains and judge between them; ignoring the source caps the answer.

Open any past question linked above to read its full mark scheme and examiner report in the Question Bank.

Arguments and counter-arguments

Is statute law the most important source of the UK constitution?

Yes

Point. Statute outranks every other source because Parliament is legally sovereign. Explanation. An Act of Parliament can override a convention, a common law rule or a treaty, so statute sits at the top of the hierarchy. Example. The Constitutional Reform Act 2005 created the Supreme Court and reshaped the senior judiciary by ordinary legislation. Evaluation. This is decisive in strict law, because no court can set aside a clear Act.
Point. The most significant constitutional changes have come through statute. Explanation. When the constitution is reshaped, it is almost always done by passing an Act. Example. Devolution, the Human Rights Act 1998 and the repeal of the European Communities Act in 2020 were all delivered by statute. Evaluation. However, the very ease of changing statute is also why critics say it leaves the constitution unprotected.

No, the others matter as much

Point. Conventions hold the day-to-day system together. Explanation. Much of how government actually runs depends on unwritten rules that no statute sets out. Example. The Salisbury Convention, the Sewel Convention and collective ministerial responsibility all shape behaviour without legal force. Evaluation. This matters, because the system would seize up if conventions were ignored, even though they are not enforceable in court.
Point. Common law and the courts have grown in constitutional weight. Explanation. Judges interpret statute, develop legal principle and police the limits of executive power. Example. Miller 2 in 2019 found the prorogation of Parliament unlawful, a purely judicial limit on the government. Evaluation. This shows statute is supreme in theory but does not act alone in practice.

Best judgement. Statute is the supreme source in strict law because Parliament is sovereign, but the constitution works only because conventions and common law fill the gaps statute leaves, so statute is first among sources rather than the whole story.

Using it in essays

30-mark: any "the UK constitution" question (2025 Q1a, 2020 Q1b).
Topic sentence: "The UK constitution is uncodified and unentrenched, drawn from five sources, with statute supreme because Parliament is sovereign."
Final judgement: statute leads, but conventions and common law make the system function.

Practise this on PantherConstitution notes Constitution walk-through

Wider context

Helpful context (background, not a spec requirement)

A simple test sorts the sources: ask whether a rule could be enforced in court. Statute, common law and incorporated treaties could be; conventions could not, which is exactly why they are the fragile part of the constitution.

Examination priority

Important Learn the five sources and the three features as the base layer. Every other subsection builds on this.

1.2 The core principles Done

Essential The three principles the whole constitution rests on: parliamentary sovereignty (Dicey's three rules), the rule of law, and the unitary or union state.

The specification

1.2The twin pillars and the nature of the state

Parliamentary sovereignty (Dicey) - Parliament can make or unmake any law, no Parliament can bind its successor, and no body can override an Act. I can do this

The rule of law - everyone, including government, is subject to the law, and like cases are treated alike before independent courts. I can do this

The UK is a unitary state where power flows from a sovereign centre at Westminster, increasingly described as a union state since devolution. I can do this

Wording above follows the Pearson specification. Tick a line only when you could answer on it without notes.

Past questions - how it has been examined

Directly: a sovereignty or core-principles theme runs through every "the UK constitution" question, such as 2025 Q1a and 2020 Q1b.
As the framing: Sample Q1a (federalism as a logical next step, source) is really a question about whether the unitary state should give way to a federal one.

Pattern. Sovereignty is the most reliable theme in the area. Have one transferable line: limited in practice, intact in law.

What examiners reward and penalise

Stronger answers separate legal from political sovereignty - in strict law Parliament remains supreme, while the limits from devolution, rights law and the courts are political and practical.
Weaker answers claim sovereignty has simply been lost, treating reversible political limits as though they were permanent legal ones.

One way to get high marks

Credited: Dicey's three rules give a precise definition of sovereignty, and the legal-versus-political distinction is the key to the top band.
Rewarded evidence: Factortame (1990) as a real but reversible legal limit while in the EU, the restoration of statute supremacy after Brexit in 2020, and Miller 2 (2019) as the rule of law constraining the executive.
Level 5: sustains the judgement that sovereignty is limited in practice but intact in law, rather than swinging to one extreme.

Open any past question linked above to read its full mark scheme and examiner report in the Question Bank.

Arguments and counter-arguments

Has parliamentary sovereignty been undermined?

Yes, in practice

Point. Membership of the EU placed a real limit on sovereignty. Explanation. While the UK was a member, EU law took priority over conflicting Acts of Parliament. Example. In Factortame (1990) the courts suspended part of the Merchant Shipping Act 1988 because it breached EU law. Evaluation. However, this limit was always reversible, and Brexit ended it, which weakens the claim that sovereignty was permanently lost.
Point. Devolution and rights law have constrained Westminster in practice. Explanation. Power has been handed to devolved bodies and the courts can now declare statutes incompatible with rights. Example. The Human Rights Act 1998 produced the Belmarsh declaration of incompatibility in 2004. Evaluation. Yet these remain repealable by a future Parliament, so the constraint is political rather than legal.

No, it remains intact in law

Point. Every limit on sovereignty has proved reversible. Explanation. If Parliament can undo a constraint by passing another Act, it was never truly bound. Example. The European Communities Act 1972 was repealed in 2020, restoring the supremacy of statute. Evaluation. This is the strongest point, because it shows the limits were borrowed, not lost.
Point. A Commons majority can still reshape the constitution at will. Explanation. Parliament can legislate on any subject and override the courts where it chooses. Example. The Safety of Rwanda Act 2024 legislated that Rwanda is a safe country, directing the courts by statute. Evaluation. This confirms that in strict law Parliament has never stopped being sovereign.

Best judgement. Parliamentary sovereignty has been limited in practice by devolution, rights law and the courts, but it remains intact in law because every limit has proved reversible, so the honest verdict is limited in practice, intact in law.

Using it in essays

30-mark: sovereignty-undermined questions, and as a theme inside any constitution essay (2025 Q1a).
Topic sentence: "Parliamentary sovereignty has been constrained in practice but never displaced in law, because every limit on it has proved reversible."
Final judgement: limited in practice, intact in law.

Practise this on PantherSovereignty grid Sovereignty sentences

Wider context

Helpful context (background, not a spec requirement)

For any apparent limit on sovereignty, ask one question: could Parliament reverse it with an ordinary Act? If the answer is yes, the limit is political, not legal, and sovereignty survives in strict law.

Examination priority

Important This is the most reliable theme in the area. Lock in the legal-versus-political distinction and four dated examples.

1.3 The uncodified constitution: strengths and weaknesses Done

Essential What the UK gains and loses by having no single document: flexibility and an evolutionary system against vagueness, weak entrenchment and concentrated power.

The specification

1.3Strengths and weaknesses of an uncodified constitution

Strength - flexibility: the constitution adapts through ordinary legislation, so major change can happen quickly with a single Act. I can do this

Weakness - weak entrenchment: rights and constitutional rules rest on ordinary statute and can be removed by the next majority. I can do this

Weakness - concentrated power: a government with a Commons majority can change the constitution almost at will. I can do this

Wording above follows the Pearson specification. Tick a line only when you could answer on it without notes.

Past questions - how it has been examined

Directly: 2024 Q1b (constitutional reform, source) rewards weighing the strengths and weaknesses of an unwritten, flexible system.
As the framing: 2025 Q1b (whether it is time for a codified constitution, source) is decided largely on whether the uncodified system's flexibility outweighs its lack of entrenchment.

Pattern. The strengths-and-weaknesses balance is the engine of the whole codification debate. Frame it as flexibility and democratic control against vagueness and weak protection of rights.

What examiners reward and penalise

Stronger answers judge each feature both ways - flexibility is a strength when it allows reform and a weakness when it leaves rights unprotected - rather than sorting features into a strengths list and a weaknesses list.
Weaker answers treat flexibility as purely good and codification as purely modern, missing that the same flexibility is what makes the system hard to defend against an over-mighty executive.

One way to get high marks

Credited: the central trade-off is that flexibility and weak entrenchment are the same feature seen from two sides, which is why the constitution adapts fast but protects rights poorly.
Rewarded evidence: the Human Rights Act 1998 brought a rights framework home with one Act (flexibility), yet as ordinary statute it could be replaced, as the 2022 Bill of Rights Bill tried to do (weak entrenchment); the repeal of the Fixed-term Parliaments Act in 2022 shows reform undone.
Level 5: reaches a defensible verdict on whether flexibility outweighs the weaknesses, and carries it into the codification question.

Open any past question linked above to read its full mark scheme and examiner report in the Question Bank.

Arguments and counter-arguments

Do the strengths of the uncodified constitution outweigh its weaknesses?

Yes, flexibility wins

Point. Flexibility lets the constitution adapt without crisis. Explanation. Major change can be delivered by ordinary legislation rather than a slow amendment process. Example. The Human Rights Act 1998 brought a whole rights framework into UK law with a single Act, and devolution was created by statute. Evaluation. This is a real strength, because a fast-changing polity can update its rules as it goes.
Point. Power stays with elected representatives rather than judges. Explanation. Because there is no higher-law document for courts to interpret, the final say rests with Parliament. Example. Parliament, not a constitutional court, decided to create the Supreme Court through the Constitutional Reform Act 2005. Evaluation. This protects democratic control, though it also leaves few checks on a determined majority.

No, weak protection wins

Point. Rights and rules are only weakly entrenched. Explanation. Anything resting on ordinary statute can be swept away by the next majority. Example. The Human Rights Act is ordinary statute, and the 2022 Bill of Rights Bill sought to replace it. Evaluation. This is a serious weakness, because the protection of rights should not depend on the goodwill of the government of the day.
Point. The system concentrates power in the executive. Explanation. A government with a Commons majority can reshape the constitution almost without limit. Example. The repeal of the Fixed-term Parliaments Act in 2022 handed the power of dissolution straight back to the executive. Evaluation. This is the strongest case against the present system, since flexibility serves whoever holds the majority.

Best judgement. Flexibility is a genuine strength that has let the UK reform without crisis, but the same flexibility leaves rights weakly entrenched and power concentrated, so the strengths win only if rights protection is improved separately.

Using it in essays

30-mark: constitutional-reform and codification questions (2024 Q1b, 2025 Q1b).
Topic sentence: "The uncodified constitution buys flexibility at the price of entrenchment, so its strengths hold only where rights can be protected another way."
Final judgement: flexibility is worth keeping, but the weak protection of rights is the case the reformers get right.

Practise this on PantherCodification grid Codification paragraphs

Wider context

Helpful context (background, not a spec requirement)

The neat way to hold this subsection together is to notice that flexibility and weak entrenchment are one feature, not two. The constitution is easy to change because it is not protected, so any praise of its adaptability is also an admission of its fragility.

Examination priority

Important Master this balance first, because it is the raw material for the codification essay. Learn the same examples for both sides.

1.4 Should the UK adopt a codified constitution? Done

Essential The headline 30-mark debate: a single entrenched document for clarity and protected rights, against flexibility, democratic control and the fact the present system works.

The specification

1.4The case for and against a codified constitution

For: a codified document would bring clarity, entrench rights against an ordinary majority, and place a higher-law check on the executive. I can do this

Against: codification would reduce flexibility, transfer power from elected MPs to unelected judges, and replace a system that works in practice. I can do this

A middle position is targeted entrenchment of rights rather than a wholesale written constitution. I can do this

Wording above follows the Pearson specification. Tick a line only when you could answer on it without notes.

Past questions - how it has been examined

Directly: 2025 Q1b (whether it is time for a codified constitution, source) and 2023 Q1a (the UK needs a codified constitution, source).
Related: 2024 Q1b (constitutional reform, source) and Sample Q1b (constitutional reform, source) both invite the codification argument as their centrepiece.

Pattern. This is the banker 30-mark question for the area. Prepare a clear line of argument and three themes, not a balanced list with the verdict saved for the end.

What examiners reward and penalise

Stronger answers hold one line of argument across three themes and reach interim judgements, weighing recent cases - the Rwanda Act, the Fixed-term Parliaments Act repeal, Miller 2 - on whichever side they take.
Weaker answers list advantages and disadvantages with no overall direction, or assume codification must be right because most democracies have a written document.

One way to get high marks

Credited: the debate turns on a single axis - flexibility and democratic control against clarity and entrenched limits on power - and the best answers name that trade-off explicitly.
Rewarded evidence: the Human Rights Act 1998 as fragile ordinary statute, the Safety of Rwanda Act 2024 and the Fixed-term Parliaments Act repeal as an unchecked executive, against the Belmarsh declaration in 2004 and Miller 2 in 2019 as the present system working.
Level 5 over Level 4: sustains a single verdict, often that targeted entrenchment of rights beats a wholesale codified document, rather than concluding both sides have a point.

Open any past question linked above to read its full mark scheme and examiner report in the Question Bank.

Arguments and counter-arguments

Should the UK adopt a codified constitution?

Yes

Point. A codified document would entrench rights against a passing majority. Explanation. Rights written into a higher law could not be removed by an ordinary Act. Example. The Human Rights Act is only ordinary statute, and the 2022 Bill of Rights Bill tried to replace it, showing how exposed rights currently are. Evaluation. This is the reformers' strongest ground, because rights protection should not rest on the goodwill of the government.
Point. It would place a real check on the executive. Explanation. A higher-law constitution would stop a government rewriting the rules through its Commons majority. Example. The Safety of Rwanda Act 2024 directed the courts by statute, and the repeal of the Fixed-term Parliaments Act handed dissolution back to ministers. Evaluation. However, the same check would shift power to unelected judges, which is the core objection to codification.

No

Point. Codification would cost the flexibility that lets the constitution adapt. Explanation. A single entrenched document is slow to amend, where an Act can change the constitution at once. Example. The United States has amended its constitution on a substantive issue only rarely since 1971, while the UK delivered devolution and the Human Rights Act by statute. Evaluation. This is a strong point for a polity that has changed as fast as the UK since 1997.
Point. The present system works and there is no agreement on a replacement. Explanation. The constitution has produced stable government and protected rights without a written text, and no consensus exists on what a codified document would contain. Example. The Belmarsh declaration of incompatibility in 2004 and Miller 2 in 2019 show the courts protecting rights and limiting the executive already. Evaluation. This shifts the burden onto reformers to prove the system has failed, which they have not done.

Best judgement. The case against a wholesale codified constitution holds, because flexibility and democratic control are real strengths and there is no agreement the present system has failed, but the reformers are right that rights are fragile, so the strongest answer is targeted entrenchment of rights rather than a full written document.

Using it in essays

30-mark: the codification question in any form (2025 Q1b, 2023 Q1a).
Topic sentence: "The UK should not adopt a fully codified constitution, because flexibility and democratic control outweigh the gains, though the targeted entrenchment of rights is the part of the reformers' case that holds."
Final judgement: no to a wholesale written document, yes to entrenching rights.

Practise this on PantherCodification grid Constitution walk-through

Wider context

Helpful context (background, not a spec requirement)

A clean way to decide this question is to ask what problem codification is meant to fix. If the answer is fragile rights, the targeted fix is to entrench rights; you do not need a whole written constitution to do that, which is why the wholesale case is weaker than the rights case.

Examination priority

Important This is the headline 30-mark question for the area. Commit one line of argument, three themes, and the same six examples used across all the constitution essays.

Test Section test - 12 questions

Twelve mixed questions covering the whole area. Your most recent score shows in the top bar.

Practise this topic on Panther

Notes Walk-through Codification grid Sovereignty grid Reform since 1997 grid Flashcards Quiz

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