Bases of the two Houses
An effective bicameral system requires that the two houses of the legislature be constituted on different bases: if they are constituted in the same way they would be likely to have the same political colour and therefore not be an effective check upon each other. The federal system necessarily requires that the two houses be constituted on different bases to reflect and secure the federal character of the union. The two Houses of the Australian parliament therefore have different compositions.
The main differences between the Australian Houses derive from the representative base, method of election, and terms of office. The principal features of federal bicameralism as exemplified in the Commonwealth Parliament are:
- Effective equality of the Senate and the House in the making of laws and the performance of all other parliamentary responsibilities. The only qualification is that certain types of financial legislation must originate in the House of Representatives, and in some cases the Senate is limited to suggesting and, if necessary, insisting on amendments.
- Senators are elected on a state or territory basis, each state or territory voting as one electorate; membership of the House is based on single member electorates approximately equal in population.
- Each state irrespective of population is represented by 12 senators, each territory by 2 senators; representation in the House of Representatives is based on population.
- Distinctive methods of electing the two Houses. Senators are elected by a proportional method; the method of electing members of the House of Representatives is preferential.
- State senators are elected for terms of six years; half the senators from each state retire at three-yearly intervals. Members of the House of Representatives are elected for terms not exceeding three years. Except in the circumstances of simultaneous dissolution of both Houses, the Senate, in contrast to the House of Representatives, is a continuing House. The terms of territory senators end and begin at each election for the House of Representatives.
- Constitutional provision for resolution of disagreements between the Senate and the House over legislation originating in the House of Representatives. Such disagreements over legislation originating in the House may be resolved by simultaneous dissolution of both Houses. If, following new elections, the disagreement persists, the legislation in contention may be submitted to a joint sitting of both Houses.