CANBERRA -- The political fates of the unlikely grouping which has become known as the "Citizenship 7" -- Barnaby Joyce, Fiona Nash, Matt Canavan, Nick Xenophon, Malcolm Roberts, Larissa Waters and Scott Ludlam -- is about to be revealed.
The High Court will rule on Section 44 of the constitution, which bans foreign nationals sitting in Federal Parliament, at 2.15pm (AEDT) on Friday.
All seven cases involve sitting MPs facing the possibility of being kicked out of Parliament because they were dual citizens at the time of the last election.
So what brought them to the High Court, and what may happen next?
Joyce's problem: The father of Deputy Prime Minister Barnaby Joyce was born in New Zealand. Joyce was born in Australia and never applied for NZ citizenship. NZ has claimed him as a citizen, but his eligibility is for the High Court to decide. Ineligibility would put the Turnbull government's slim majority at risk, although Independent MP Cathy McGowan has stated she would continue to support the government on supply and confidence.
What will happen if he loses: Likely to face a by-election in the northern NSW seat of New England. Former Independent Tony Windsor is already waiting to re-contest if there's a by-election. The earliest the poll can be held is December 2.
Nash's problem: Deputy Nationals Leader Fiona Nash was born in Sydney but had a Scottish-born father. She said she believed she had to apply for citizenship of another country, but a caseworker at the UK Home Office had advised Nash they were of the first flush view that she was a British citizen by descent.
What will happen if she loses: She would be replaced by a special count of last year's Senate ballots. The Liberal and Nationals had a joint state ticket, so Nash's most likely replacement would NSW Liberal, and slush fund whistleblower, Hollie Hughes.
Canavan's problem: The former resources minister stepped down from Cabinet role, but stayed in the Senate after discovering he was a dual Italian citizen by descent. He originally blamed a 2006 citizenship application by his mother, but later conceded he has been an Italian citizen since he was two.
What will happen if he loses: He would be replaced by a special count of last year's Senate ballots. Canavan's likely replacement would be former LNP senator and grand-niece of the late Neville Bonner, Joanna Lindgren.
The problem for Roberts: Born in India to a Welsh father and an Australian mother. The High Court has already ruled Senator Roberts was a British citizen at the time of the July 2016 election. His lawyer has argued the case against him and his possible breach of the Constitution is "un-Australian" and stated he was "entitled to put out of his mind that he was a British citizen". It was also found the One Nation senator attempted to check and renounce his citizenship using email addresses which were shut down more than half a decade earlier.
What will happen if he loses: He would be replaced by a special count of last year's Senate ballots. The most likely replacement for Roberts would be the next candidate on the Queensland One Nation Senate ticket, Fraser Anning. He and his wife were facing bankruptcy action in the Federal Court, but this legal action has now been withdrawn.
Xenophon's problem: The South Australian is the son of a Cyprian father and Greek mother, but is a dual Australian-British citizen by descent, as a result of his father emigrating to Australia from a British territory.
What will happen if he loses: Xenophon would be replaced by a special count of last year's Senate ballots. He has already flagged his intention to quit federal politics to run in the South Australian state election next March. The likely replacement would be Tim Storer, fourth on the NXT ticket at last year's federal election.
Ludlam's problem: The former Greens senator was born in New Zealand and came to Australia when he was three years old, but never renounced his dual NZ citizenship in what he admitted was a "ridiculous oversight".
He is not contesting his right to sit in parliament.
What will happen if he loses: He has already resigned from the Senate. Ludlam would be replaced by special count of last year's Senate ballots. 22 year old Jordon Steele-John is next in line for the position because he was third on the Greens Senate ticket at last year's election.
Waters problem: The former Greens senator was born in Canada and moved to Australia as an infant. Unknown to her, Canadian law had changed a week after she was born and required her to have actively renounced Canadian citizenship.
She is not contesting her right to sit in parliament.
What will happen if she loses: She's already resigned from the Senate. Waters would be replaced by special count of last year's Senate ballots. And her most likely replacement is a serious blast from the political past with the number two on the 2016 Greens QLD senate ticket being the former leader of the Australian Democrats, Andrew Bartlett.HighCourtSeven:EverythingNeedKnowAboutFriday'sDualCitizenshipDecision