VCE Legal Studies Unit 4 Constitution and law reform deep-dive 2026
Unit 4 turns on the structure of the Constitution (division of powers between Commonwealth and states; separation of legislative, executive and judicial power), section 109 inconsistency (three forms, state law invalid to the extent of inconsistency), the limited rights protection (five express rights plus the implied freedom of political communication, a limitation on legislative power, not a personal right), the High Court's role in interpreting the Constitution and reviewing the validity of laws, and the means of reform (the s 128 referendum with its double majority for the Constitution; parliamentary and court-driven reform for statute and common law). Accuracy of cases, sections and dates is decisive.
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How Unit 4 fits into VCE Legal Studies
Unit 4 "The people, the law and reform" is where VCE Legal Studies leans hardest on Australian constitutional law and the relationship between Parliament and the courts. It runs across two Areas of Study: "The people and the law-makers" and "The people and reform". Unit 4 is the part of the course that distinguishes VCE from interstate equivalents, and it generates the stimulus-based items that reward precise constitutional reasoning.
This guide covers the division and separation of powers, section 109 inconsistency, the express rights and the implied freedom of political communication, the role of the High Court, statutory interpretation and precedent, and the means of constitutional and statutory law reform. It closes with a model extended-response paragraph. The recurring marking theme is accuracy: cases, section numbers and dates must be real and well established, and a defensible judgement must be reached on evaluation questions.
The division of powers
The Australian Constitution distributes legislative power between the Commonwealth and the states. This is the division of powers.
- Exclusive powers. Only the Commonwealth may exercise these (for example, the power to coin money under s 51(xii) read with s 115, and customs and excise under s 90).
- Concurrent powers. Both the Commonwealth and the states may legislate (most s 51 heads, such as taxation, marriage and trade). Section 109 resolves any resulting conflict.
- Residual powers. Matters not listed for the Commonwealth remain with the states, which retain plenary legislative power (for example, criminal law, education, public transport).
Over time, Commonwealth law has expanded into areas once dominated by the states, particularly through the external affairs power (s 51(xxix)), used to implement treaties (Commonwealth v Tasmania (1983) 158 CLR 1, the Tasmanian Dam case), and the corporations power (s 51(xx)) (New South Wales v Commonwealth (2006) 229 CLR 1, the WorkChoices case).
The separation of powers
The Constitution also divides Commonwealth power among three arms of government. This is the separation of powers.
Legislative power (Chapter I): the Parliament makes law. Executive power (Chapter II): the Crown and government administer and enforce law. Judicial power (Chapter III): the courts interpret and apply law and resolve disputes.
The separation of the judicial power is strictly enforced (only Chapter III courts may exercise the judicial power of the Commonwealth, per R v Kirby; Ex parte Boilermakers' Society of Australia (1956) 94 CLR 254). The legislative and executive arms are partly fused because, under responsible government, ministers sit in Parliament.
The separation of powers protects against the concentration of power and supports the independence of the judiciary, which underpins the rule of law and the fair determination of disputes between citizens and the state.
Section 109 and inconsistency
Where both the Commonwealth and a state have legislated in a concurrent area and the laws conflict, section 109 resolves it.
When a law of a State is inconsistent with a law of the Commonwealth, the latter shall prevail, and the former shall, to the extent of the inconsistency, be invalid.
There are three forms of inconsistency:
- Direct inconsistency, simultaneous obedience impossible. The two laws impose contradictory obligations.
- Direct inconsistency, state law alters or impairs the Commonwealth law. Even where obeying both is possible, the state law diminishes the Commonwealth law's operation (Clyde Engineering Co Ltd v Cowburn (1926) 37 CLR 466).
- Indirect (cover the field) inconsistency. The Commonwealth law manifests an intention to cover the field exhaustively, so any state law in that field is inconsistent (Ex parte McLean (1930) 43 CLR 472).
The consequence is partial: only the inconsistent portion of the state law is invalid, and it revives if the Commonwealth law is later repealed. Leading cases include the Amalgamated Society of Engineers v Adelaide Steamship Co Ltd (1920) 28 CLR 129 (the Engineers Case), which established that Commonwealth heads of power are read on their natural meaning and prevail in concurrent areas, and Commonwealth v Australian Capital Territory (2013) 250 CLR 441, in which the High Court struck down the Marriage Equality (Same Sex) Act 2013 (ACT) because the Marriage Act 1961 (Cth) covered the field.
A Commonwealth law "covers the field" when, properly construed, it shows an intention to be the complete and exhaustive statement of the law on a subject. Any state law operating in that same field is then inconsistent under s 109 and invalid to the extent of the inconsistency, even if it does not directly contradict the Commonwealth law.
Express rights and the implied freedom
The Constitution contains only a small number of express individual rights. It is not a bill of rights.
Section 41: the right to vote in Commonwealth elections (largely transitional after R v Pearson; Ex parte Sipka (1983) 152 CLR 254). Section 51(xxxi): acquisition of property on just terms (JT International SA v Commonwealth (2012) 250 CLR 1, the tobacco plain packaging case, confirmed not every impairment is an "acquisition"). Section 80: trial by jury for indictable Commonwealth offences (read narrowly: Parliament chooses whether an offence is indictable, Cheng v The Queen (2000) 203 CLR 248). Section 116: freedom of religion at the federal level (narrowed in Attorney-General (Vic); Ex rel Black v Commonwealth (1981) 146 CLR 559, the DOGS case). Section 117: freedom from state-residence discrimination (read broadly in Street v Queensland Bar Association (1989) 168 CLR 461).
The implied freedom of political communication is derived from the requirement in ss 7 and 24 that members of Parliament be "directly chosen by the people".
- Australian Capital Television Pty Ltd v Commonwealth (1992) 177 CLR 106 first recognised the freedom, striking down a ban on political advertising.
- Lange v Australian Broadcasting Corporation (1997) 189 CLR 520 restated it as a limitation on legislative power, not a personal right, and set a two-step test: does the law burden the freedom, and is it reasonably appropriate and adapted to a legitimate end compatible with representative and responsible government?
- McCloy v New South Wales (2015) 257 CLR 178 refined the second step into structured proportionality (suitability, necessity, adequacy of balance).
- Brown v Tasmania (2017) 261 CLR 328 struck down anti-protest provisions targeting forestry protests.
- Calling the Constitution a bill of rights
- It is not. The express rights are limited to ss 41, 51(xxxi), 80, 116 and 117.
- Treating the implied freedom as a personal right
- It is a limitation on legislative and executive power, not a personal cause of action.
- Saying s 80 guarantees a jury for all serious offences
- It applies only where Parliament has designated the offence as indictable.
The role of the High Court
The High Court of Australia is the apex court and the guardian of the Constitution. Its constitutional roles include:
- Interpreting the Constitution. The High Court gives meaning to constitutional terms and heads of power. The Engineers Case (1920) reset the method toward the natural meaning of the words.
- Determining the validity of laws. The Court can strike down a Commonwealth or state law that exceeds constitutional power or breaches an express or implied limitation (for example, Commonwealth v Australian Capital Territory (2013)).
- Acting as a check on power. By enforcing the separation of judicial power and the implied freedom, the Court constrains the legislature and executive.
The High Court cannot change the words of the Constitution; only a referendum under s 128 can do that. It can, however, develop the interpretation of those words over time, which has the practical effect of shifting the balance of power within the federation.
Statutory interpretation and precedent
Beyond constitutional cases, the courts make law by interpreting statutes and developing the common law.
Statutory interpretation. Victorian courts apply the purposive approach mandated by the Interpretation of Legislation Act 1984 (Vic) s 35, preferring a construction that promotes the purpose of the Act. The Commonwealth equivalent is the Acts Interpretation Act 1901 (Cth) ss 15AA and 15AB, the latter permitting extrinsic materials such as the second reading speech where a provision is ambiguous. The leading authority is Project Blue Sky Inc v Australian Broadcasting Authority (1998) 194 CLR 355, which begins with text and context, with purpose informing the choice between candidate meanings.
The doctrine of precedent. Under stare decisis, lower courts in a hierarchy must follow the ratio decidendi (the legal reasoning essential to the decision) of higher courts in the same hierarchy; obiter dicta are persuasive only. Courts manage precedent through four techniques: distinguishing (material facts differ), reversing (an appellate court reverses the same case), overruling (a higher court rejects a precedent from an earlier case) and disapproving (signalling disagreement without overruling). The High Court is the only court that may overrule its own previous decisions, and does so cautiously.
Means of law reform
Law reform happens by two routes: changing the Constitution and changing statute and common law.
Changing the Constitution: the referendum
The only way to alter the text of the Constitution is a referendum under s 128. A bill to alter the Constitution must pass both houses (or be passed twice by one house after a three-month interval), then be put to electors. It succeeds only with a double majority: a national majority of voters, and a majority of voters in a majority of states (four of the six states).
Of 45 referendum proposals put to Australians since federation, only eight have succeeded. Successful proposals include the 1967 referendum (allowing the Commonwealth to make laws for Aboriginal Australians and to count them in the census). The 2023 referendum on an Aboriginal and Torres Strait Islander Voice to Parliament failed to achieve a double majority. The double-majority requirement makes formal constitutional change difficult, which is one reason the High Court's evolving interpretation carries so much weight.
Changing statute and common law
Outside the Constitution, the law is reformed through:
- Parliamentary lawmaking. Parliament can pass new Acts, amend existing Acts, codify common-law rules (the Native Title Act 1993 (Cth) codifying Mabo v Queensland (No 2) (1992) 175 CLR 1) or abrogate court decisions (the Wrongs (Animals Straying on Highways) Act 1984 (Vic) reversing Trigwell v State Government Insurance Commission (1979) 142 CLR 617).
- Court-driven development. Courts interpret statutes and, where Parliament is silent, develop the common law incrementally (the recognition of native title in Mabo).
- Law reform bodies. The Victorian Law Reform Commission, the Australian Law Reform Commission and parliamentary committees investigate and recommend reform, which Parliament may then enact.
- Influences on Parliament. Petitions, demonstrations, the use of the courts to highlight a defect in the law, the work of the media and pressure groups, and royal commissions all influence the parliamentary agenda.
The dialogue between Parliament and the courts is constant: courts interpret, Parliament responds by amending, and the cycle continues.
Check your knowledge
A mix of definitional, application and exam-style questions covering Unit 4. Answer all under exam conditions, then check against the solutions block. Allocate roughly 1.5 minutes per mark.
- Distinguish between the division of powers and the separation of powers. (4 marks)
- Explain the three forms of inconsistency under section 109 of the Constitution, citing one case for at least two of them. (5 marks)
- Identify the five express rights in the Constitution by section number and subject. (5 marks)
- Explain why the implied freedom of political communication is described as a limitation on legislative power rather than a personal right, citing one case. (4 marks)
- Describe two roles of the High Court in relation to the Constitution. (4 marks)
- Explain the difference between codification and abrogation, giving one example of each. (4 marks)
- Explain the process for altering the Australian Constitution under section 128, including the double-majority requirement. (5 marks)
- Discuss the significance of section 109 for the division of powers, referring to at least two leading cases and to the practical expansion of Commonwealth law over time. (8 marks)
- Q1
- The division of powers distributes legislative power between the Commonwealth and the states; the Commonwealth holds enumerated (mostly concurrent) powers under s 51 and the states retain residual plenary power. The separation of powers divides Commonwealth power among the legislature (Chapter I), the executive (Chapter II) and the judiciary (Chapter III). The key contrast: the division of powers is federal (Commonwealth versus states), while the separation of powers is functional (between the three arms of government).
- Q2
- First, direct inconsistency where simultaneous obedience is impossible because the laws impose contradictory obligations. Second, direct inconsistency where the state law alters, impairs or detracts from the Commonwealth law even though obeying both is possible (Clyde Engineering Co Ltd v Cowburn (1926) 37 CLR 466). Third, indirect inconsistency where the Commonwealth law covers the field, so any state law in that field is inconsistent (Ex parte McLean (1930) 43 CLR 472).
- Q3
- Section 41: the right to vote in Commonwealth elections. Section 51(xxxi): acquisition of property on just terms. Section 80: trial by jury for indictable Commonwealth offences. Section 116: freedom of religion at the federal level. Section 117: freedom from discrimination on the basis of state residence.
- Q4
- The implied freedom restricts what laws Parliament may validly make: a law that effectively burdens political communication and is not reasonably appropriate and adapted to a legitimate end is invalid. It does not confer a positive right on an individual to communicate, and it gives no personal cause of action; it can only be used to challenge the validity of a law. Lange v Australian Broadcasting Corporation (1997) 189 CLR 520 expressly characterised it this way.
- Q5
- Any two: (1) interpreting the Constitution and giving meaning to its terms and heads of power (the Engineers Case (1920) 28 CLR 129); (2) determining the validity of Commonwealth and state laws and striking down laws that exceed power or breach a limitation (Commonwealth v Australian Capital Territory (2013) 250 CLR 441); (3) acting as a check on legislative and executive power by enforcing the separation of judicial power and the implied freedom.
- Q6
- Codification is Parliament adopting a common-law rule into statute; for example the Native Title Act 1993 (Cth) codified the recognition of native title in Mabo v Queensland (No 2) (1992) 175 CLR 1. Abrogation is Parliament reversing a court decision by statute; for example the Wrongs (Animals Straying on Highways) Act 1984 (Vic) abolished the immunity left in place by Trigwell v State Government Insurance Commission (1979) 142 CLR 617.
- Q7
- Under s 128, a bill to alter the Constitution must be passed by an absolute majority of both houses of Parliament (or passed twice by one house after a three-month interval where the houses disagree). It is then put to the electors at a referendum. To succeed it must achieve a double majority: a majority of all voters nationally, and a majority of voters in a majority of states (at least four of the six states). Only eight of 45 proposals have succeeded, which shows how difficult formal constitutional change is.
- Q8
- A complete answer states the text of s 109 (state law invalid to the extent of inconsistency with a Commonwealth law), explains that it operates only in concurrent areas of the division of powers, and uses cases. The Engineers Case (1920) 28 CLR 129 established that Commonwealth heads of power are read on their natural meaning and prevail under s 109 in concurrent areas, rejecting reserved state powers. Commonwealth v Australian Capital Territory (2013) 250 CLR 441 shows cover-the-field inconsistency invalidating a state or territory law. Over time, the combined effect of broad interpretation of s 51 powers (external affairs in the Tasmanian Dam case (1983) 158 CLR 1; the corporations power in the WorkChoices case (2006) 229 CLR 1) and s 109 has been a steady expansion of Commonwealth law into areas once dominated by the states. Judgement: s 109 is the central mechanism that resolves federal conflict in favour of the Commonwealth and, alongside expansive interpretation of Commonwealth powers, has shifted the federal balance markedly toward the Commonwealth since 1920.