^Steele Hall joined the Liberal party in 1976 on the break-up of the Liberal Movement. Hall resigned from the Senate in 1977 and Janine Haines, who had joined the Democrats on the break-up of the Liberal Movement, was appointed to fill the vacancy on 14 December.
In accordance with section 13 of the Constitution, following a double dissolution of Parliament, the terms for state senators commence on 1 July preceding the election, i.e., on 1 July 1975. The first five senators elected in each State were allocated full six-year terms ending on 30 June 1981 while the other half were allocated three-year terms ending on 30 June 1978.[2]
There were two significant changes that affected the composition of the Senate.
The Northern Territory and Australian Capital Territory were to be represented in the Senate for the first time.[3] The terms of senators representing the territories commenced on the date of the election and ended at the dissolution of the House of Representatives, in this case the December 1977 election.
A person appointed to a casual vacancy must be from the same political party as the original senator and is appointed until the end of the original term.
Austin Lewis had been appointed under the former system, however his term was extended to the end of the original term of 30 June 1981 as a result of the 1977 referendum.[4][5] The first vacancy occurring under the new process was caused by the resignation of Steele Hall, who had been a member of the Liberal Movement but had joined the Liberal party in 1976 on the break-up of the Liberal Movement. Janine Haines was appointed to replace Hall, having been third on the Liberal Movement ticket in 1975,[6] however she was no longer a member of the Liberal Movement, having joined the Democrats.[7]
^ abLiberal Ivor Greenwood died on 13 October 1976; Liberal Austin Lewis was appointed to fill the ensuing vacancy on 17 December. Lewis's term would have ended in December 1977, being the earlier of the next election for the House of Representatives or the Senate,[8] however his term was extended to the end of Greenwood's original term on 30 June 1981 as a result of the 1977 referendum.[4][5]
^ abSenator Steele Hall had been elected as a member of the Liberal Movement, however the party broke up and he joined the Liberal party in June 1976. Hall resigned from the Senate on 16 November 1977 to contest the House of Representatives seat of Hawker. DemocratsJanine Haines was appointed to fill the ensuing vacancy on 14 December.
^ abcdThe term of a territory senator ends at the dissolution of the House of Representatives which was December 1977.