Senate changeovers would have been due on 1 July 1985 and 1 July 1988, while the term of the new House of Representatives would have expired in 1986. Bob Hawke decided to call a regular federal election for December 1984 after only 18 months in office, to bring the two election cycles back into synchronisation. Allocation of long-term and short-term seats In order to return to the normal arrangement of half the state Senators being contested at each election, following a double dissolution, section 13 of the Australian Constitution requires the senate to divide the state senators into two classes, with three-year and six-year terms. This has traditionally been done by allocating long terms to the senators elected earliest in the count. The 1984 amendments to the Commonwealth Electoral Act required the Australian Electoral Commission to conduct a notional recount as if only half the seats were to be elected, which was seen as producing a fairer allocation. This alternative allocation has not yet been used. Following double dissolution elections in 1987 and 2016, the order-elected method continued to be used, despite Senate resolutions in 1998 and 2010 agreeing to use the new method. South Australian double dissolutions Under section 41 of the South Australian constitution, if a bill is passed by the House of Assembly during a session of Parliament and in the following Parliament after a general election for the lower house is rejected by the Legislative Council on both occasions, it is permitted for the Governor of South Australia to either issue a writ for the election of 2 additional members of the Legislative Council or to dissolve both houses at the same time to elect an entirely new Parliament. As the upper house consists of 22 members, with 11 elected statewide at each general election for an 8-year term at a quota of 8.33%, this would result in an election for all 22 members at a quota of 4.35%. Although it has been threatened, this South Australian double dissolution procedure has never been used. See also Electoral system of Australia Explanatory notes References Australian Senate Federal elections in Australia Parliament of Australia Political terminology in Australia