The Westminster system is the basis of government in Australia, at the state, territory and federal level. It is based on the British model of responsible government.

Under this system public sector employees serve the people of their state, territory or country by implementing the Government's policies, decisions and programs. This includes:

  • understanding that ministers and the Cabinet are responsible for deciding policy, and are free to accept or reject the advice of Departments and other agencies
  • accepting that although executives are under the direction of their Secretary or agency head, they have a clear duty to respond promptly and professionally to ministers’ requests for advice or information
  • providing advice to ministers that is apolitical, 'frank and fearless’ and non-partisan.

Key components

The Westminster System comprises:

  1. a head of state - the Sovereign or their representative 
  2. an elected Parliament, made up of one or two houses
  3. government formed by the political party or coalition that has majority support in the Lower House of Parliament
  4. Prime Minister or Premier, who heads the Government
  5. ministry, drawn from members of Parliament – usually members of the Government  –  who exercise executive authority and are accountable to the Parliament
  6. an independent judiciary
  7. an apolitical professional public sector that provides the Government with impartial advice and implements the Government's policies and programs.

Separation of powers

At the heart of the Westminster system is the concept that power is separated between the three branches of government, creating a system of checks and balances. These branches are:

  • The Legislature: the Parliament, which makes the laws
  • The Executive: the Governor, Prime Minister, Premier, ministers, departments and agencies, which are responsible for implementing laws
  • The Judiciary: the courts, which interpret and apply the law.

The separation of powers is considered one of the cornerstones of fair government. In Australia’s Westminster system of parliamentary democracy, the separation is not total because the executive is drawn from and accountable to the Legislature.

Separation of powers diagram


The Premier is the head of the Government; they lead the party or coalition that has majority support in the Legislative Assembly (the Lower House of Parliament). This individual advises the Governor on the appointment of ministers, and determines the makeup of departments and other agencies, and allocates legislation to the purview of certain ministers.


The Premier and ministers together constitute the Cabinet, which decides the Government’s priorities, policies and legislative program.

Ministers bring their proposals to Cabinet, which then makes decisions that are collective, confidential and binding on ministers.


Ministers decide on policy and are accountable to the Parliament for their decisions. One convention of the Westminster system is ministerial responsibility, whereby  ministers administer and bear responsibility for the actions of a department or agency within their control.

Public Servants

Another key element of the Westminster system  is a permanent public service. Within this public service department, secretaries and heads of agencies are responsible for the general conduct and management of their agencies; public servants are appointed on merit; and all act in accordance with core values.

Public servants work under the direction of their departmental secretary or agency head. Within this context they support ministers' efforts to:

  • develop and advise on policy options and draft legislation
  • implement the Government’s decisions, policies and programs
  • deliver services to the community
  • manage the state’s resources, assets and finances.

Further information