Why does Parliament have two chambers and not just one?

The simple answer to this question is because it is a rule in the Australian Constitution – the rules about how Australia is governed. Section 1 of the Constitution says the Australian Parliament is made up of the Senate, House of Representatives and the King.

However, the reason for this rule is more complex. 

Many features of Australia’s system of government were modelled on the British and the United States’ systems of government. The British Parliament has two houses and so does the United States Congress. Australia’s House of Representatives and Senate were designed similarly to the United States:

• The number of members of the House of Representatives from each state is determined by the population of that state.
• Each state has the same number of senators.

This structure was designed to prevent states with more people like New South Wales and Victoria from dominating Parliament. If there was only one house based on population, the laws made could potentially only benefit larger cities like Sydney and Melbourne. Having population-based representation in the House of Representatives and equal representation for all states in the Senate helps to ensure laws benefit the entire country. A bicameral Parliament – one with two houses – means that bills are more carefully examined and checked to make sure they are in the best interest of all Australians.