section 109 of the Australian Constitution and its significance for the division of powers

What this dot point is asking

VCAA wants you to explain how section 109 of the Constitution resolves conflict between Commonwealth and state laws. Expect a 5-8 mark medium response in Section A or B.

The answer

The text

Section 109 of the Constitution of the Commonwealth of Australia provides:

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.

This is the rule of Commonwealth supremacy in concurrent areas of legislative power.

The three forms of inconsistency

The High Court has identified three forms of inconsistency.

1. Direct inconsistency: simultaneous obedience impossible. The state law and Commonwealth law impose directly contradictory obligations. Example: a state law that requires conduct the Commonwealth law prohibits.

2. Direct inconsistency: state law alters, impairs or detracts from the Commonwealth law. Even where simultaneous obedience is possible, the state law diminishes the operation of the Commonwealth law (Clyde Engineering Co Ltd v Cowburn (1926) 37 CLR 466).

3. Indirect (cover the field) inconsistency. The Commonwealth law manifests an intention to cover the field exhaustively. Any state law in that field is inconsistent. (Ex parte McLean (1930) 43 CLR 472.)

The consequence

The state law is invalid "to the extent of the inconsistency". This is a partial, not total, invalidation: only the inconsistent portion is struck down. If the inconsistent Commonwealth law is later repealed, the state law revives.

Leading cases

Amalgamated Society of Engineers v Adelaide Steamship Co Ltd (1920) 28 CLR 129 (the Engineers Case). The Engineers Case reset constitutional interpretation. The High Court rejected the doctrines of reserved state powers and implied intergovernmental immunities, holding that Commonwealth laws made under s 51 powers applied to state-owned enterprises. This established the modern approach: Commonwealth heads of power are interpreted on their natural meaning and prevail under s 109 in areas of concurrent power.

McBain v Victoria (2000) 99 FCR 116; Re McBain; Ex parte Australian Catholic Bishops Conference (2002) 209 CLR 372. The Federal Court found a Victorian law restricting IVF to married women was inconsistent with the Sex Discrimination Act 1984 (Cth). The relevant Victorian provision was invalid to the extent of the inconsistency.

Commonwealth v Australian Capital Territory (2013) 250 CLR 441. The High Court struck down the Marriage Equality (Same Sex) Act 2013 (ACT) on the ground that the Marriage Act 1961 (Cth) (as it then stood) was intended to cover the field of marriage. The ACT Act could not operate concurrently. (The Commonwealth subsequently amended the Marriage Act 1961 (Cth) to recognise same-sex marriage in 2017.)

Significance for the division of powers

The Australian Constitution distributes legislative power between the Commonwealth and the states. The states have plenary legislative power; the Commonwealth has enumerated powers under s 51 (and a few other heads). Most s 51 powers are concurrent (both can legislate). Section 109 is the device that resolves the conflict where both have legislated.

The practical effect over time has been steady expansion of Commonwealth law into areas formerly dominated by state law, particularly through:

• the external affairs power (s 51(xxix)), used to implement international treaties (e.g. the Commonwealth v Tasmania (1983) 158 CLR 1 (the Tasmanian Dam case));
• the corporations power (s 51(xx)) (e.g. the WorkChoices case, New South Wales v Commonwealth (2006) 229 CLR 1);
• the financial corporations power and the taxation power.