The Prime Minister's threat to Senate crossbenchers to either pass industrial relations legislation or possibly face a double dissolution election may herald a rare political event.
It has been criticised by some as either a move designed to intimidate smaller opponents, or to take control of the upper house of parliament.
Only six times since the formation of the Commonwealth of Australia over 110 years ago has the Constitutional measure been used.
Kristina Kukolja takes a look at what a double dissolution election is, and its place in Australian political history.
When a government finds itself without the ability to pass its legislation successfully through both houses of parliament, Australia's Constitution allows for a special mechanism that can disrupt the electoral cycle - a double dissolution election.
To understand how and why this works, it's necessary to look at the history of Australia's parliamentary democracy.
Based on the British Westminster system, the federal, or executive, government is responsible to the parliament, or the legislative arm of government.
In Australia the parliament comprises two chambers.
Federal elections are held every three years.
Government is formed by the party with a majority in the lower house - the House of Representatives.
The upper house, the Senate, is a house of review.
Professor of politics at the University of Adelaide in South Australia, Clem MacIntyre, says dissolving both houses for re-election - a double dissolution election - is a serious endeavour.
"A normal election sees all of the House of Representatives up for election -- all 150 members -- and half of the Senate. That's half of the state senators. There are 12 senators representing each state and two from each territory. At a normal half-Senate election, as it's called, six of those senators from the states are elected to six-year terms and the two from each territory are elected to three-year terms. At a double dissolution election all 76 of those seats become vacant and each state will elect 12 new senators to fill the state spots and the territories two each. Of the 12 state senators six will be elected to serve three-year terms, and six will be elected to serve six-year terms. So, that rotation of half the Senate going at each election is back in sync again."
For a double dissolution election to occur, the government needs what's known as a "trigger bill".
Professor Macintyre explains it refers to a specific piece of legislation which the two houses of federal parliament cannot agree to pass.
"The Constitution says that if there's a disagreement between the House of Representatives and the Senate over a bill, then the government has the capacity to seek an early election to resolve that. So, a bill must be passed in identical form by the lower house and blocked by the Senate twice, and there must be a three-month gap between the first block and the second block. If that happens, the prime minister has what's called a "trigger bill" and can go to the Governor General and say, 'The Senate is refusing to pass this bill which the lower house is supporting. I'm requesting a double dissolution to clean out the whole of the House of Representatives as well as the whole of the Senate - and have a fresh election, after which if we are elected, that bill could be reput to the parliament."
The Governor General represents Australia's head of state, the Queen, and is expected to act on the advice of the prime minister and dissolve both houses of parliament.
And only six times since the federation of Australia's colonies in 1901 has this happened.
The first double dissolution election was called in 1914 over union employment in the public service.
The most recent was in 1987 - again by a Labor government, but this time using legislation proposing the introduction of a national identity card.
In 1950, the conservative Liberal-National government led by Prime Minister Robert Menzies had hoped a bill banning the Communist Party of Australia would act as a trigger for a double dissolution vote, but it was ultimately passed by a Labor-dominated Senate.
Dr Barry York is an historian at the Museum of Australian Democracy at Old Parliament House in Canberra.
He says, in 1951 Mr Menzies tried again - using the failure of another bill to ultimately secure a majority in the upper house.
"Menzies' government was opposed to the attempt by the previous Labor party government headed by Ben Chifley to nationalise the banks, and the dispute or deadlock in 1951 was to do with what was called 'The Commonwealth Bank bill' which, in effect, rescinded any of the attempts to nationalise the banking sector. And that was an example of where the risk involved in a double dissolution (election) paid off for the government because Menzies ended up back in power with - if I remember correctly - an increased majority."
Dr York warns that the move doesn't guarantee government control over both houses of parliament.
"It's interesting from a politician's point of view, or prime minister's point of view who wants to go down that path - it's almost like the toss of a coin because half of them have returned the government and half haven't. Added to that is the complication, of course, the big risk which is that the Senate in Australia has considerable power compared to Senates in other Commonwealth countries and other parliamentary democracies. It's a house of review, but also it can reject a bill from the House of Representatives and it can decline to pass such a bill, or it can amend a bill. So, even if a double dissolution results in the return of the government, there's no guarantee the Senate will be a cooperative one."
And if, even after a double dissolution election, the Senate refuses to pass the trigger legislation, both houses of parliament can be called for a joint sitting.
Australia's current parliament expires on November 11, and an early double dissolution election must be called outside of its final six months.
