At a Federal level, we have two houses of parliament, an upper and lower house (otherwise known as the Senate and the House of Representatives). Being a Federation, the idea was that the Senate would be the states house with equal representative from each state. The proportion of representatives in the House of Representatives, by contrast, depended on the population of the State. However, as predicted by some last century, in reality the Senate is no more a states house than Australia is a classless society. Senators vote on party lines, not state lines. They are mere pawns, as seen by the decision of the Senate in 74/75 to block supply acting on the advice of the leader of Liberal Party in the House of Representatives.
In order to produce an Act of Parliament, a Bill must be approved by both houses of parliament and the Crown. Since Crown assention is a formal one (as the Crown acts on the advice of the ministers), then in reality the Bill must just be approved by both houses of parliament. Bills may be introduced into either House, but most are introduced in the House of Representatives. If the Senate refuses to pass a Bill passed by the House of Representatives three times, then the Governor General, if so advised by the ministers, may dissolve the Senate and the House of Representatives simultaneously which will result in the election of a new House and Senate.
Sometimes of course this process is abused.
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