When a Senate seat representing one of the six states becomes vacant, Section 15 of the
Australian Constitution requires the
parliament of the relevant
state to choose a replacement. This is done in a joint sitting of the upper and lower houses (except for
Queensland, which has a
unicameral parliament). In the event that the state parliament is not in session, the
Governor of the state (acting on the advice of the state's
executive council) may appoint the replacement, but such an appointment lapses if it is not confirmed by a joint sitting within 14 days after the beginning of the next session of the state parliament.
Prior to 29 July 1977, it was an established convention, but not a constitutional requirement, that the state parliament choose (or the governor appoint) a replacement from the same
political party as their predecessor. It had also been the practice for the relevant party to provide a list of suitable names to the state premier, and for the state parliament to make the choice. In 1975, both these conventions were breached - in the former case, twice.
On 9 February 1975, the
New South Wales Labor Senator
Lionel Murphy resigned from the Senate to take up an appointment as a judge of the
High Court of Australia. On 27 February, the NSW
Liberal Premier
Tom Lewis appointed
Cleaver Bunton, a former long-serving Mayor of
Albury, who was not affiliated with any political party. Bunton sat as an independent senator.
On 30 June 1975, the
Queensland Labor Senator
Bertie Milliner died suddenly. The Labor Party gave only one replacement name to the
Country Party Queensland Premier Joh Bjelke-Petersen - that of
Mal Colston. However, on 3 September, at Bjelke-Petersen's instigation, the
Parliament of Queensland appointed
Albert Field to the vacancy. Although he had been a member of the Labor Party for 30 years, Field was now openly critical of the Labor government of
Gough Whitlam, and he was immediately expelled from the party for accepting the appointment. Field took his seat in the Senate as an independent. However, there were doubts as to his constitutional eligibility to sit at all. Although he had resigned from the Queensland Department of Education the day before he was appointed, the Education Act (Qld) required three weeks notice of resignation, and it was arguable that he was therefore still in Crown service (this technicality had been ignored many times in the past). The Labor Party immediately challenged Field's appointment in the
High Court, and he was on leave from the Senate from
1 October for the remainder of his short-lived term, which ended when the parliament was dissolved on
11 November.[SUP]
[12][/SUP]
On 21 May 1977, a
referendum was held on the question of whether the Constitution should be changed to require future Senate casual vacancies to be filled by a member of the party represented by the former senator at the time of their election, if the state parliament chooses to fill the vacancy. The referendum was passed and came into effect on 29 July 1977. Where a senator had been elected representing a certain party, and changed allegiances to a different party mid-term, and then died or resigned, the replacement senator would be a person representing the first party. This was first implemented when Senator
Steele Hall, who at the time of his election represented the
Liberal Movement but had later changed to the
Liberal Party of Australia, resigned and was replaced by
Janine Haines. She represented the
Australian Democrats and was chosen because the Liberal Movement had merged with the Democrats.
