There's a reason double dissolution threats are often not carried out, explains Professor Anne Twomey for the Drum.
The Senate was established as a continuing body. Senators have fixed six year terms, with half of them coming up for election every three years. The rationale was that the Senate would provide stability and continuity, evening out the swings in voter opinions shown in House of Representatives elections.
One consequence, however, is that the Senate is unlikely to reflect the composition of the government of the day. This can lead to deadlocks over bills. To deal with this, the Constitution includes a procedure by which the whole of the Senate can be dissolved and elected afresh.
To get the system back into kilter after a double dissolution, the Senate must decide, when it first meets, which Senators get six year terms and which only get three years. In the past this has been done according to the order in which Senators were elected, but it is up to the Senate to decide, with some predicting a Hunger Games style fight to the death.
The term of Senators is then notionally dated back to the first day of July preceding the day of the Senator's election. This means the Turnbull Government has a strong incentive to hold the election in July 2016, because if it did so in May, the terms of Senators would be shortened by a year, requiring a half-Senate election in just two years.
Another timing problem is that the dissolution of the Senate may not take place within six months before the expiry of the House of Representatives. This means that the Houses would have to be dissolved by May 11, followed by an election in early July, resulting in a long election campaign.
A double dissolution can only be held if the Governor-General is persuaded that the constitutional requirements have been met. This means that the Senate must reject or "fail to pass" a bill that has already been passed by the House of Representatives, or amend it in a way that the House of Representatives rejects. Then after three months, the House must pass the same bill again, and the Senate must reject, fail to pass or unacceptably amend it again. Only then can it trigger a double dissolution.
How does one know when the Senate has "failed to pass" a bill? In New South Wales there is a time period of two months for it to pass, but the Commonwealth Constitution contains no such indication, leading to considerable uncertainty.
Can it be said that the Senate has "failed to pass" the bill concerning the Australian Building and Construction Commission (ABCC)? It meets the first part of the test, having been passed by the House and rejected by the Senate after being considered by a committee. In February 2016, over three months later, the bill was again passed by the House of Representatives. It was introduced into the Senate on February 4 and again referred to a Senate Committee, for report on March 15, 2016. Is this enough for it to have "failed to pass"? There are two relevant precedents.
In 1951, Menzies wanted to hold a double dissolution election on communism. But he didn't have a trigger. So he reintroduced a bill on Commonwealth banking and taunted Chifley to reject it so that a double dissolution could be held. Chifley took Evatt's advice that if the bill was referred to a committee, it would not amount to failure to pass it. The bill was sent to a committee, but Menzies convinced the Governor-General to hold a double dissolution based upon the failure to pass it. Labor members complained that the Governor-General (a former Labor Premier) should have got advice from the Chief Justice (a former Liberal Attorney-General) about whether it was valid. Nonetheless, no one challenged the validity of the election.
In 1974, Whitlam used as one of a number of double dissolution triggers the Petroleum and Minerals Authority Bill. It had been received by the Senate on the last sitting day in December 1973 and was scheduled for debate at the next sitting day, in February 1974. Had it failed to pass? In a subsequent High Court challenge, the majority held that it had not failed to pass and was therefore not a valid double dissolution trigger. The Senate was entitled to a reasonable time in which to perform its duty with respect to bills. It was not sufficient that certain Senators had stated they would reject the bill. What was relevant was the actions of the House.
If Turnbull took the Menzies approach of claiming that the reference of the bill to a parliamentary committee amounted to a failure to pass it, it is unlikely that he would get away with it without a challenge. However, such action is unnecessary, as the Government already has a double dissolution trigger in the Fair Work (Registered Organisations) Amendment Bill 2014. Just as Menzies used his double dissolution election to campaign on communism, even though his trigger for the election was different, so too could a Turnbull Government campaign about the need for an Australian Building and Construction Commission, even if it is not a formal trigger for the election. The only relevance of it not being counted as a trigger would be that it could not then be put to a joint sitting after the election, if the Senate still failed to pass it.
It may be that, given these technical problems, the Turnbull Government takes the view that it is all too hard to pull the double dissolution trigger and waits it out for a general election later in the year. If so, it would be in line with most other Governments, for which threats of double dissolutions, though numerous, have been all sound and fury, signifying nothing.