Explainer: how does a Liberal leadership spill work?

It’s on. AAP/Mick Tsikas

Chief Government Whip Philip Ruddock has confirmed that the Liberal party room will vote on a leadership spill motion when it meets next Tuesday. After days of speculation, backbench West Australian MP Luke Simpkins announced on Friday afternoon that he would move the motion, to be seconded by fellow WA backbencher Don Randall.

It seems like we were just here. For the last five years, speculation, party instability and ill-discipline and a leader simply unable to get on the front foot have become hallmarks of Australian politics. It was less than two years ago that Kevin Rudd returned to the office of prime minister after having been deposed by his deputy Julia Gillard back in 2010.

This time, however, it’s the party that promised to bring political stability back to government that is in danger of imploding.

On Tuesday, Prime Minister Tony Abbott will face a leadership spill that threatens to unseat him after less than 18 months in the job. The reasons as to why the party finds itself in this mess are up for debate.

Having gone through this pain in quick succession, Rudd, on his return to office in 2013, took the power to select Labor Party leaders away from the sole hands of the parliamentary wing and gave it, in part, to its ordinary members.

However, the Liberal Party has retained a very quick and simple method of selecting its leader.

A leadership spill can be called by any Liberal member of the House of Representatives or the Senate. If the motion for the spill is seconded, a motion to elect a new leader will be put to the 102 Liberal Party MPs. For the motion to be successful, it needs to get at least 52 votes (so a majority plus one).

If the motion is passed, the leadership position is declared vacant and an election will be held to fill the role.

What happens next will have implications not only for the final outcome, but also the unity of the parliamentary Liberal Party. If, for example, Abbott recontests the leadership and no-one challenges, then he has consolidated his position and will enjoy a greater sense of legitimacy from within the party room.

However, if someone does challenge Abbott, then it will be a fractured party room that must choose between taking a chance on a new leader or sticking with the incumbent. Once again, to win a candidate must get at least 52 votes.

There is also the possibility of more than two candidates contesting the leadership. This occurred in 2009 when Abbott won the leadership against the incumbent, Malcolm Turnbull, and Joe Hockey. If this was to occur, a round of elections would be held, with the candidate that won the lowest number of votes eliminated until just two candidates remained. Again, from those two, the candidate that wins at least 52 votes would become leader.

The phones of all MPs won’t have a moment to cool down. Yet, no matter what the result on Tuesday, the Liberal Party has suffered immensely from this instability. The only silver lining is that the next election could be up to two years away.