Senate crossbenchers John Madigan, Ricky Muir, Bob Day and David Leyonhjelm

The three short sitting days this week will feel like three of the longest sitting days this year, with the government, Nick Xenophon and the Greens teaming up to pass Senate voting reform legislation in the face of strong opposition from the other crossbench senators and Labor. It is likely to be an all-out fight for the future of the Senate ahead of an expected double dissolution election later this year. What’s in it for all the parties involved?

Coalition: The government started this week by extending the Senate’s hours in order to give time for 11 pieces of legislation to be considered. Most of the legislation is not controversial, except for Commonwealth Electoral Amendment Bill, which would bring about the changes to Senate ballot papers to allow voters to have optional preferential voting, above and below the line. On Tuesday the Senate will sit until 10.30pm. On Wednesday the Senate will sit from 9.30am until 11.10pm. And on Thursday the Senate will sit from 9.30am with no set time to finish. This means if the crossbench and Labor attempt delaying tactics to prevent Senate voting reform from passing, the Senate could sit until the early hours of Friday morning.

If it passes the Senate voting reform legislation this week, the government would then have the means to clear out the crossbench senators who have frustrated the Coalition’s attempts to pass some of its legislation (dating back to the 2014 budget) for the past two years. It is widely expected that if the legislation passes, the government will likely call a double dissolution election, which, coupled with the Senate voting changes, could remove the majority of the crossbench senators.

Prime Minister Malcolm Turnbull has told the crossbench that all this could be avoided if the legislation reinstating the Australian Building and Construction Commission were passed, but it hasn’t been put up for debate this week.

Labor: Labor had been initially in favour of amendments to Senate voting, but it is now opposed to the changes. It has argued the process has been rushed in order to set up the possibility of a double dissolution outcome that would deliver a Coalition majority in the Senate, and a means for the government to pass all the legislation it desires. This has been contested by ABC election analyst Antony Green. Labor is appealing to the Greens to oppose the Senate voting reform legislation because if it passes, the government will use it to trigger a double dissolution election and then pass the ABCC legislation, which the Greens oppose.

Greens: Greens leader Richard Di Natale told ABC Radio National this morning that the Greens had been advocating for Senate voting reform for over a decade, and it was originally part of their deal with Julia Gillard in 2010. He views backing this legislation as consistent with this policy, despite any potential impact it might have on a double dissolution trigger, and changes to the make-up of the Senate if the Coalition does go to an election early.

Xenophon: The current Senate voting system cost Nick Xenophon’s running mate a spot at the last election, and Xenophon has, as a result, backed the government’s Senate voting reform legislation. He has escaped most of the heat for backing the government’s position.

Muir: In announcing the Senate voting reform, Turnbull all but name-checked Motoring Enthusiast Party Senator Ricky Muir as the reason the change was necessary. Muir was elected to the Senate with just 0.51% of the vote and 17,122 first preference votes at the 2013 election, when the quota to get in was over 483,000 votes. Muir is going to attempt to call Turnbull’s bluff on the ABCC legislation and will try to bring the legislation to a vote this week. This will have two potential outcomes. Firstly, it will show the government is disingenuous in its threats for the crossbench and simply wants the voting reform to pass in order to be able to call a double dissolution election. Secondly, it could cause troubles for the government to be able to use the ABCC legislation as a trigger for the double dissolution.

The government could argue that because the ABCC legislation had “failed to pass” the Senate, even though the Senate has not formally rejected it a second time, the Governor-General should call for a double dissolution election. If the government rejects Muir’s attempt to bring a vote on for the legislation this week, that argument would be harder to make. The government is not inclined to vote for debating the ABCC legislation because, as part of a deal to extend the Senate sitting time, the Greens demanded only legislation they are “comfortable with” would come up for debate.

Leyonhjelm: Similarly, Liberal Democrat Senator David Leyonhjelm is attempting to expose the Greens on this by bringing on the Greens’ own legislation for marriage equality up for a vote, thus delaying other pieces of legislation from being debated. The numbers in the Senate are now potentially there, and it could be the first time any of the attempts to pass marriage equality would be successful in either chamber of Parliament. If the Greens vote against voting on it, Leyonhjelm will argue they are compromising their values to support the government.

Di Natale this morning, however, argued that there was no point in bringing it to a vote now if there were still a chance it could be voted down; it would just embolden those opposed to marriage equality ahead of the plebiscite to be held after the election if the Turnbull government is re-elected. But the Greens have long argued for a free vote in Parliament, and they have not, in the past, been opposed to bringing on legislation for a vote, even if it is ultimately defeated.

Other factors: If the voting reform legislation passes, and the government does want to go to an election early, the government might have to show its hand this week. If the budget is brought forward a week early to May 3, instead of May 10, then the Speaker will notify the House of Representatives at the end of this week when Parliament will next sit. The Senate will also need to vote on a sitting outside the existing agreed sitting period if the budget were brought forward.  Bringing forward the budget would allow the government to pass a supply bill (Labor will not oppose this) to keep government running during the election.