The constitutional framework
The Constitution provides that "The Senate shall be composed of senators for each State, directly chosen by the people of the State, voting, until the Parliament otherwise provides, as one electorate". Each Original State had initially six members of the Senate and now has twelve. The Parliament is authorised to increase the number of senators elected by each state subject to the qualification that "equal representation of the several Original States shall be maintained and that no Original State shall have less than six senators". Senators representing the states are elected for terms of six years, half the Senate retiring at three yearly intervals except in cases of or following simultaneous dissolution of both Houses. A state may not be deprived of its equal representation in the Senate by any alteration of the Constitution without the consent of the electors of the state.