Constitutional crisis looms as Parliament enters uncharted waters.
The more likely scenarios from here are:
1. Rudd takes the leadership and survives a no confidence motion on the floor of Parliament.
He would need the support of five of the seven crossbenchers. Tony Windsor has indicated Mr Rudd would not get his vote, while Rob Oakeshott and Peter Slipper have said they would decide if the situation arose. Kevin Rudd can count on the support of Bob Katter, Craig Thomson and Adam Bandt. In this scenario, Mr Rudd would be able to determine the date of the election and would not necessarily have to run to the polls. (this also assumes no LAB rats on him in the vote, which can’t be assumed.)
2. Rudd takes the Labor leadership but loses a no-confidence motion.
A “constructive vote” would mean a vote of confidence in Mr Abbott would follow a vote of no-confidence in Mr Rudd. In this scenario, the Governor-General would almost certainly have to appoint Mr Abbott as caretaker Prime Minister until an election can be held.
3. Rudd takes over after Parliament has risen on Thursday.
He could avoid all questions of confidence by proroguing Parliament and requesting that Ms Bryce call an election. Under the constitution, Labor would have a maximum 63 days to go to the polls - meaning an election in mid to late August.
4. Rudd takes over after Parliament has risen but does not call an immediate election.
Under this scenario, Ms Bryce would be compelled to sound out the crossbenchers as to whether they support the new Prime Minister. If there is any uncertainty she could recall Parliament to test his support through a vote on the floor.
5. Bill Shorten emerges as a “circuit breaker” leader
As the mother-in-law of Mr Shorten, the Governor-General would be cornered by a perceived conflict of interest. Ms Twomey said: "The Governor-General would have the trust of the people but the perception of a conflict of interest would be too great. She would probably have to leave the country and appoint Marie Bashir as the governor of the largest state [NSW] to do her job.
6. No spill, Julia Gillard remains Prime Minister and a September 14 election.
Julia Gillard survives the spill and the September 14 election proceeds.
And the hottest item on tonight’s TV will be … State of Origin League (NSW v Queensland)