Policy Brief, 2025-26

The Commonwealth Parliament's place in Australia’s federal structure

Parliament, Government and Politics

Author

Law and Bills Digest section

Go to section

Issue

The Commonwealth Parliament’s power and relationship with other levels of government is inherently complex. Though it can only legislate in some areas, the Commonwealth can lead debate, influence policy or exercise financial dominance to drive change in others. Understanding these opportunities and constraints is important in determining how desired policy outcomes can best be achieved.

Key points

  • The Constitution provides the ultimate legal statement of Australia’s federal structure. It grants the Commonwealth Parliament certain powers and sets out relevant limits and guarantees.
  • The states retain broad legislative powers but Commonwealth laws prevail where inconsistencies arise.
  • Given its financial dominance, the Commonwealth may influence state policy or actions through financial grants.
  • Beyond its legislative powers, the Commonwealth may influence national policy across jurisdictions through Australia’s cooperative federal relations system.

Context

Australia’s federal structure commenced in 1901 when the former colonies united under the Constitution and a central Commonwealth Government. Commonwealth, state and territory government roles and responsibilities are partly prescribed by the Constitution, with the remainder a complex mix of convention, agreements, legal precedents and politics.

The Constitution sets out, in varying degrees of detail, the structure of the Commonwealth Parliament, the legislative powers of Parliament, the Commonwealth executive, judicial and financial structures and powers, as well as the relationship between the Commonwealth and the states.  Under our constitutional system the executive branch, under the Governor-General, is drawn from and is responsible to the parliamentary branch, while the judicial branch remains separate.

Powers of the Parliament

Unlike the states’ broad plenary legislative powers, the Constitution (predominantly section 51) gives the Commonwealth Parliament only certain specified legislative powers. Some of these are exclusive to the Commonwealth (such as those relating to customs duties, defence or Commonwealth places) while others remain concurrent, or shared with the states.

The High Court has typically adopted a broad interpretation of the Parliament’s powers. In this context, certain powers may now have a wider scope than initially anticipated, notably:

  • the corporations power, which supports much of Australia’s industrial relations law
  • the external affairs powers, which supports significant elements of Australia’s environmental and human rights legislation.

Importantly, a valid Commonwealth law will always prevail over an inconsistent state law, to the extent of that inconsistency (under section 109).

Determining a legislative provision’s constitutionality often involves significant complexity and consideration of its terms and effects. Accordingly, careful deliberation on the constitutional basis of proposed legislation should occur on a case-by-case basis, with the High Court being the ultimate authority for deciding such questions.

Limitations and guarantees

The Constitution contains limitations and guarantees on the Commonwealth’s exercise of powers. While not providing for personal rights and freedoms (analogous to the United States Constitution), it does explicitly constrain some Commonwealth and state legislative powers through provisions such as:

  • Section 116, which limits the Commonwealth’s power to make laws regarding religion.
  • Section 117, which prevents the states imposing discriminatory laws on each other.

Additionally, the High Court has found the Constitution, and the system of government it establishes, implies other limitations and guarantees. These include freedom of political communication, separation of judicial from executive and legislative powers, and the doctrine of limited intergovernmental immunities. 

Political communication

The High Court has held the Constitution implies a freedom of political communication, as a necessary part of our representative and responsible government. However, this freedom is not a personal right but a limitation on legislative or other government power. Notably it is also not an absolute limitation on legislation that may burden the freedom, but may allow for limitations that satisfy certain thresholds such as being a proportionate response to a legitimate policy goal.

Separation of powers

The separation of powers doctrine has evolved into an important aspect of democratic governments. It divides government into legislative, executive and judicial branches to provide a series of checks and balances on the exercise of power.

Australia’s Constitution and system of responsible government includes some overlap between the legislative and executive branches. This occurs through the executive, under the Governor-General, drawn from elected parliamentarians, who are dually responsible to Parliament and voters. In this way our Parliament may hold the executive branch to account to a certain extent through questions, votes and committees. In contrast, the separation between the functions of the judicial branch and the other branches remains distinct and important.

Intergovernmental immunities

Intergovernmental immunities are an important limiting principle under the federal system to ensure the Commonwealth and state governments can exist as independent entities. The doctrine, set out in the Melbourne Corporation case and further developed since, states that neither the Commonwealth nor state governments can significantly interfere, through legislation or executive action, with each other’s existence or operation as governments.

Other levels of government

The territories

Under the Constitution (section 122) the Commonwealth can legislate for the government of the territories. This power remains despite the Commonwealth having passed self-government Acts for each of the mainland territories to make and administer their own laws.

The states

The Constitution (sections 107 and 108) preserves the state governments’ broad powers to legislate and govern. These powers remain subject to the Constitution and subordinate to any valid Commonwealth laws on the same matters (under section 109). State constitutions are also recognised in and subject to the Constitution (under section 106).

Local government

The Constitution makes no mention of local government, which is provided for under respective state legislation. Commonwealth relations with local governments, and its funding of them for certain purposes, is supported by constitutional heads of power relevant to those purposes or is done through the states as tied grants.

The Parliamentary Education Office also provides a further detailed summary of the three levels of Government in Australia and their respective powers and responsibilities.

Grants to states and the vertical fiscal imbalance

Over time the Commonwealth has developed a comparatively disproportionate share of the national revenue capacity. This is largely due to the Commonwealth’s broad taxation powers and their interpretation by the High Court, along with the fact that as the Commonwealth legislates more broadly in an area it shares with the states it leaves less scope for the states to legislate. When combined with states’ large service delivery requirements (such as health and education), this ‘vertical fiscal imbalance’ creates a high degree of financial dependence. Accordingly, the Commonwealth can exert financial leverage over state policy, beyond the scope of its enumerated constitutional heads of power.

This fiscal imbalance is primarily addressed through the Commonwealth’s ability to make conditional payments to the states under section 96. This section provides the Commonwealth with the power to grant financial assistance to a state on ‘such terms and conditions as the Parliament thinks fit.’

In addition to the many smaller grants that may be made to the states under section 96 or other specific heads of power for specific purposes, the Commonwealth, states and territories have developed a Federal Financial Relations (FFR) system. This system includes joint funding agreements and GST revenue sharing arrangements that account for a significant amount of government spending at both Commonwealth and state and territory level.

Cooperative federalism

Beyond its legislative powers, the Commonwealth may influence national policy across the states and territories through a process known as cooperative federalism. This process involves the Commonwealth, state and territory governments working together through intergovernmental forums to develop policies and/or legislative responses to issues of cross-jurisdictional importance or responsibility.

Australia’s current cooperative federal relations system includes:

These mechanisms are important in developing nationally coordinated responses to issues falling outside a singular responsibility. Such responses can range from determining broad policy settings, including through harmonising laws in various jurisdictions or adopting identical model legislation, to cases where states refer specific legislative powers to the Commonwealth and accept a single national law.

However, gaining agreement across the various stakeholders and governments is often not simple or fast. In some cases consensus may be impossible, leading to reforms being unevenly adopted across jurisdictions.