How will Turnbull get the money needed to govern if he calls a double dissolution?

Malcolm Turnbull is fond of saying that we need to be less risk averse. Now the question is whether he will follow his own advice.

He is waving around the possibility of a double dissolution in early July, a course that would carry both dangers and potential high gains for him, although how they’d balance out is unpredictable.

Turnbull has repeatedly said that he expects the election at the normal time – between August and October – which would mean only half the Senate would face the people with the House of Representatives.

But he has also declared a double dissolution – taking out the whole Senate – a “live option”, and recently the odds on this have shortened, especially as the government looks to a deal with the Greens to change the Senate voting system to squeeze out “micro” players in future elections.

On Sunday night the government was expressing confidence that agreement would be secured early this week, removing a major obstacle to a double dissolution.

Without an agreement, a double dissolution would be counterproductive – another lot of small players would likely appear, perhaps more than now.

On Sunday, Deputy Prime Minister Barnaby Joyce said if the Senate became “inoperable, then … we have a right, a constitutional right, to go to a double dissolution and we’ll always keep that option up our sleeve.”

The government denies it is just raising a double dissolution as a threat, but you might wonder when you look at that pathway. It’s rather like investing a million or two in an attractive but not entirely secure start-up venture.

The problems hinge on dates, and they are tight.

Given the government is committed to bringing down a budget on May 10, the double dissolution would have to be called on May 11, for July 2, 9 or 16 (the last possible date). The July date is needed to avoid cutting the next parliamentary term very short.

This means Turnbull would be taking a big gamble on his and Scott Morrison’s budget. This will contain income tax cuts, but with the GST off the table these can no longer be mega. Some other taxes will have to be adjusted to pay for them.

Presumably the government would avoid the nasties being a surprise via early leaks or announcements.

Still, launching an election before the reaction to the budget plays out – and the opposition leader has even had a chance to give his parliamentary reply – would take a certain chutzpah.

And there are some practical issues. Once the end of the financial year ticks over the government needs a fresh appropriation of money. It’s not that all the cash instantly runs out but it would be impossible to get by because it would be weeks before the new parliament convened.

Passing some appropriation would need Senate co-operation. ABC election analyst Antony Green says: “If they need to pass supply and Labor says ‘not on your nelly, Bill Shorten hasn’t given his speech’, it’s all over”.

If Turnbull wanted to call an election on May 11, he might have to seek supply funds earlier, during the current parliamentary session which ends in mid-March.

That would put the Senate in an interesting dilemma – no-one wants to revisit the blocking of supply. But the government would also be flagging its double-dissolution plan, effectively starting the campaign many weeks before parliament was dissolved.

Green also says that given the brief window in May for calling the double dissolution, Turnbull would need to avoid surprising Governor-General Sir Peter Cosgrove on the question of “trigger” bills.

The government has undisputed “triggers” for a double dissolution – bills rejected twice with the required period in between. But it would also want to make the legislation, already rejected once, for the re-establishment of the Australian Building and Construction Commission (ABCC) a trigger, so it could raise a storm about industrial thuggery. However the Senate has voted to send this legislation to a committee that doesn’t report until March 15, just before the parliament rises on March 17 for its pre-budget break.

If the Senate doesn’t deal with that legislation – which on present indications it would reject – in those couple of days, there would be no opportunity for it to do so before the double dissolution was called.

The government would argue this was a “failure to pass” under the constitution and so the ABCC was a trigger bill. But Turnbull would have to be confident this argument was acceptable to Cosgrove – it would be embarrassing to be sent back by Cosgrove to redo the paperwork at the last moment.

A double dissolution after a deal on Senate reform would clear away annoying micro players, and likely though not automatically produce an easier Senate for a re-elected Turnbull government. It would allow that government to pass “trigger” bills at a subsequent joint sitting.

But the complications, including and especially the one about getting the money, would make jumping out of the double-dissolution starting blocks a messy process. The campaign itself would be very long – the longest since 1984, one that became very hard going for then-prime minister Bob Hawke.

Who would benefit from an extended campaign can’t be predicted but it would certainly be more difficult for either side to control than a conventional one.