What are the main roles of the Australian Senate?

The Australian Senate has three main roles in the federal Parliament. It is a house of review for legislation passed by the House of Representatives, a house of equal state representation that protects smaller states and territories, and a check on the executive government through its committee and scrutiny work.

The review role means that most legislation passed by the House of Representatives must also pass the Senate to become law. The Senate considers bills section by section in committee of the whole, can propose amendments, can defer consideration to standing or select committees that take evidence and report, and can ultimately reject bills outright. When government and Senate disagree, the Constitution provides a double-dissolution mechanism (section 57) to resolve persistent deadlocks.

The state-representation role flows from section 7 of the Constitution, which requires equal numbers of senators from each state regardless of population. With 12 senators from each of six states, plus 2 from each of the two territories, the Senate gives Tasmania (about 575,000 people) the same number of senators as New South Wales (about 8.4 million). The principle protects smaller states from being outvoted on every issue by the population-based House.

The executive-check role operates through Senate committees, Senate Estimates, and Question Time. Senate standing committees in eight portfolio areas conduct inquiries into legislation, executive decisions, and matters of public concern. Senate Estimates, held three times a year, sees ministers and senior public servants questioned in detail about programmes and spending. The Senate's regular use of these mechanisms has earned it a reputation as one of the more powerful upper houses among Westminster parliaments. Since 2007, no federal government has held a Senate majority, making negotiation with crossbench senators a central feature of Australian politics.