The Deputy Prime Minister had some bad news and wanted to tell his great mate "Wacka" in person before he informed the Nationals party room and then the Parliament.

But Wacka was chairing a meeting of the Senate's regulations committee, and so in the end, Queensland Nationals senator Barry O'Sullivan had to break the news: Joyce had discovered he was a New Zealand citizen and so was possibly ineligible to sit in Parliament.

"I was very shocked," says Wacka.

He wasn't the only one. When Joyce stood up in the House of Representatives later that morning, incredulous intakes of breath could be heard around the nation. Joyce has built his political career on being as dinkum as they come: the Tamworth boy who grew up on a farm, loves rugby and wears Akubra hats to black-tie balls.

He'd also been out furiously capturing the moral high ground for the government on the citizenship crisis. Not only had he insisted his citizenship was not in doubt but when the Greens were rocked by dual citizenship resignations last month, Joyce opined Scott Ludlam and Larissa Waters had no other option but to resign. "It's black and white," he told the ABC.

Then came a call from the New Zealand high commission late last week. The New Zealand Department of Internal Affairs discovered Australia's Deputy Prime Minister and Minister for Agriculture and Water Resources could have a problem. Joyce was born in Australia in 1967, but his dad, Jim, was born in New Zealand, only moving to Australia in 1947. This made the Deputy Prime Minister an official Kiwi under citizenship by descent.

Cat, meet pigeons.

Joyce is the fifth federal MP to be referred to the High Court over their citizenship status in the past month (his deputy, Fiona Nash, sensationally became the sixth just before Parliament rose on Thursday night. And crossbench senator Nick Xenophon became the potential seventh on Friday morning).

But critically, the Deputy Prime Minister is the first and so far only lower house MP in the group. Despite its precarious one-seat majority, the Turnbull government is putting on a brave face. Armed with advice from the Solicitor-General (which has not been publicly released), the Coalition insists Joyce is just fine, thanks for asking.

As Joyce told Parliament on Monday: "The government is of the firm view that I would not be found to be disqualified by the operation of section 44 of the constitution from serving as the member of New England." Prime Minister Malcolm Turnbull went a step further when he boldly declared Joyce was "qualified to sit in the house and the High Court will so hold".

People who have seen the Solicitor-General's legal advice step it out like this: Joyce was not born overseas, he is not on a New Zealand register of citizens, he has not applied for NZ citizenship, no one else has applied for it on his behalf, and he has never acquiesced, consented or sworn an oath to New Zealand.

Quite simply, he has no allegiance to Australia's closest friend.

But as section 44 states, a person is disqualified from Parliament if they are "under any acknowledgment of allegiance, obedience, or adherence to a foreign power, or is a subject or a citizen or entitled to the rights or privileges of a subject or citizen of a foreign power".

How the High Court will rule is not certain, as other constitutional experts point out.

University of NSW professor George Williams has said Joyce could be in "some difficulty". "The only question here is, 'Is he regarded under New Zealand law as a citizen?' That's not a question of activation; in fact, this can happen without a person's knowledge or consent," Williams said earlier this week.

Sydney University's Anne Twomey can see a more flexible interpretation of section 44, but at the same time has questioned the government's confidence on the matter. "It may be that the High Court tries to wind these things back, so if you were born in Australia, and you haven't taken any steps to gain any foreign citizenship, then maybe that is enough to avoid disqualification," she says.

At this stage, all we know for sure about the High Court is that it will hold a directions hearing on Thursday to work out what process will be followed. We still don't know whether the court will consider all MPs with citizenship questions in one lot, or whether they will be done separately. Or who will argue the case against Joyce.

Williams, the dean of the UNSW law school, says it will take some months at least for the matter to be resolved. The government is predicting it will be done and dusted by Christmas, but this is not a given.

Joyce's predicament and his decision – unlike his colleague Matt Canavan's – to stay in cabinet and keep his deputy PM's badge, has sent Labor into a whirlwind of indignation. The opposition has hammered home the "government in chaos" narrative, and understandably so. Nash's late-night revelation and decision to stay in cabinet will only add to the argument.

On Thursday, Leader of Opposition Business Tony Burke tried to suspend standing orders (one of Tony Abbott's favourite stunts when in opposition) to move a motion attacking Turnbull for continuing to "accept the vote of the Deputy Prime Minister while his constitutional qualifications are in doubt" and calling on the PM to make Joyce resign from cabinet.

Until the High Court finds otherwise, however, Williams says there is no legal need for Joyce (or anyone else under a cloud) to resign or stop voting. But this prompts the obvious question: what happens if Joyce is ruled ineligible?

The government's numbers in the lower house would slip from 76 to 75, leaving them without a majority (Labor is on 69, with five crossbenchers). While it looks highly unlikely any of the crossbench would accept the speakership, to give the government back an extra vote, this won't be necessary for the Coalition to survive.

Even if others on the crossbench are having misgivings, independent Cathy McGowan at this point says she will guarantee confidence and supply. This means the government will still be able to hang its shingle on the door.

One extreme option, as Cory Bernardi suggested on Thursday, is for Turnbull to suspend Parliament until there is a definite decision. But given that a negative High Court finding for Joyce would likely coincide with the two-month Christmas break, this looks like overkill.

This week, locals in Joyce's northern NSW electorate of New England appeared relaxed at the news their local member was also a Kiwi. As one woman interviewed by the ABC New England North West noted, "New Zealand and Australia are the same anyway." A Tamworth man said: "He's an Aussie and a good one."

But if Joyce is ruled ineligible, it won't matter how good an Aussie he is, the High Court will order a byelection. There is no set time period here, although it could take a couple months, especially if it clashes with the festive season.

Joyce, a former Queensland senator, switched houses and states when he won New England in 2013. He retained the seat comfortably with 58.5 per cent of the two-candidate preferred vote in 2016, despite a high-profile challenge from independent Tony Windsor, who held the seat from 2001 to 2013.

A byelection now, however, would come as the Coalition struggles in the polls. The most recent Newspoll on August 7 had Labor ominously ahead, 53 to 47 per cent.

Bede Burke is a Tamworth egg producer and chairman of the NSW Nationals. He isn't a fan of byelections.

"The difficulty of byelections is [they're] often seen as a way of belting up a government," he says. But Burke also has full confidence in Joyce, whom he describes as a "champion" of agriculture and water issues. "We love him."

Windsor won't rule out another challenge, but there is no doubt Joyce would stand again. Fairfax Media also spoke to senior Nationals who are all but certain about winning New England, should another vote be required, with one noting: "I've got no worries."

University of New England senior lecturer in politics Tim Battin adds that even though there are big differences across the electorate (for example, between the university town of Armidale and the country music hub of Tamworth), there have be no obvious changes to local dynamics since the 2016 vote.

"I don't sense any great shift," he says.

"This is getting silly," is how one Nationals MP describes their response to Joyce's Monday announcement (well before the news broke that Nash could be a British citizen). NSW MP Mark Coulton, who holds the neighbouring electorate of Parkes, was also taken aback by the news, but says the party is sticking together.

"We're a pretty tight bunch," he says. "We tend to hunt as a pack."

Publicly, and privately, the Nats are backing their leader, whom they see as a "rock star" performer with an impressive ability to talk to voters in language they relate to. If there are any recriminations, they are directed at the constitution and its particular requirements for sole citizenship. As Burke notes of Joyce, "He's only human, too."

But the hits keep coming for the party that is crucial to keeping the Liberal Party in government. As of Friday morning, four out of the party's 21 members have been referred to the High Court. Three – Joyce, Nash and Canavan – are for citizenship issues. NSW MP David Gillespie was referred by Labor in July due to a possible business interest clash.

And then there is the O'Sullivan question, too. On Thursday, Channel Ten reported that the Queensland senator might have a section 44 problem as well, as his family's construction company is subcontracted to work on a project which receives federal government funds. Section 44 also disqualifies federal MPs if they have any "direct or indirect pecuniary interest in any agreement with the public service of the Commonwealth".

There are some behind-the-scenes changes afoot. Last week, the NSW branch beefed up its nomination forms with added questions, but it will take more than that for the party to recover. At the rate they're sending MPs to the High Court, the Nats are making the Greens look positively rigorous in their administration processes.

The view from Coalition strategists has been that the Turnbull government should dig in and ride out the Joyce situation. Turnbull will visit Tasmania over the weekend, and regional NSW next week. He will talk about jobs, national security and the kitchen table concerns of "ordinary" Aussies, trying to move the conversation on.

This is easier said than done. As a Turnbull booster in the commentariat wrote this week, the rest of the year, politically speaking, looks like a write-off for the government.

If the citizenship fiasco doesn't suck up all the oxygen, the same-sex marriage postal vote promises to distract from "business as usual" at least until the end of the year. And that's before you contemplate the devilishly difficult debate in the party room on the Clean Energy Target, over which numerous conservative MPs are prepared to go to the wall. Then there's Abbott's regular contributions to public debate.

To further complicate things, as 2018 rolls around, the Coalition will (likely) be drawing ever closer to 30 consecutive negative Newspolls, the measure Turnbull used to justify ousting Abbott. The questions about the timing of the next federal election – not due until 2019, but quite likely next year – will start in earnest in January.

How will the government get clear air from here?