Jacqui Lambie has paid tribute to her father as she tearfully announced her resignation from the Senate after discovering her UK citizenship by descent.
The Tasmanian Senator asked the British Home Office for clarification of her status after Senate President Stephen Parry quit over citizenship doubts.
After the confirmation came back on Tuesday morning, Senator Lambie phoned her father - who arrived in Australia from Scotland as a child - to tell him and hours later made her announcement in a six-minute speech to parliament.
"It is with great regret that I have to inform you that I had been found ineligible by way of dual citizenship," Senator Lambie said.
"I love my father to death and hope to not blame him for this. He has done nothing for which to apologise and he has been my strongest supporter, my loudest cheer squad and my closest adviser."
Senator Lambie said she had worked hard to be voice for veterans, people on welfare and pensioners.
She did not know what her next step would be but in the short term, she would be helping her Jacqui Lambie Network win seats in the Tasmanian state election.
The outgoing crossbencher warned the Turnbull government against using her absence as an "opportunity" to pass legislation which she opposed.
"To do so would be a mistake," she said.
Indigenous Affairs Minister Nigel Scullion paid tribute to Ms Lambie on behalf of the National Party.
"Your particular passion that you bring to particular issues, I think, has been very effective," Mr Scullion told the Senate. "You've had an absolute unique and remarkable contribution to this place."
Fellow Indigenous Senator Pat Dodson also farewelled the Tasmanian in an emotional tribute.
"This side of Jacqui, the Indigenous side, aggrieves me the most to see her go," he said.
Mr Dodson said Ms Lambie's Indigenous heritage has been put to one side because of a Constitution that refuses to recognise the First Peoples.
"It's an absolute tragedy that our Constitution was written by all these white folks that never bothered to consider and incorporate the First Peoples in it."
Her replacement is expected to be the next Jacqui Lambie Network candidate on the 2016 ticket, Devonport Mayor Steve Martin.
However, Mr Martin's position as mayor could render him ineligible under section 44 of the constitution disqualifying anyone with an "office of profit under the crown."
It's been speculated Senator Lambie may run for the Tasmanian federal seat of Braddon if Labor MP Justine Keay is forced to a by-election due to her citizenship problems.
Tasmania first to the last
Jacqui Lambie said she would tell Tasmanians first, and the independent senator kept her word.
Speaking exclusively to Tasmania Talks radio, Ms Lambie broke down this morning when she confirmed she will be resigning from the Senate after receiving verification of her dual British citizenship.
"When the Senate starts this morning at 12.30pm, after prayers, I will be resigning from the Senate. It’s been made quite clear that because of my father, I am also Scottish," she said.
"Before I go into the Senate, now that I know, I just want to let Tasmanians know, because they deserve to know before anyone else does."
British authorities confirmed early this morning Ms Lambie is a UK citizen by descent through her father, who was born in Scotland.
Ms Lambie said she was devastated to learn of the news.
"Obviously I'm doing my autobiography and I've gone back over Dad's stuff and straight away I just thought, 'oh my god,' my whole guts just dropped and I thought I'm in trouble here," she said.
She spoke to her father last week to confirm the worst.
"I'm on the phone to Dad saying please what's going on and it all unravelled in about two or three days, and by Thursday last week I just rang him at 7.30 in the morning and I said, 'Dad I'm gone aren't I' (crying) and he said 'you know what sweetheart I think we're gone'," she said.
Senator Lambie has become the eighth federal politcian to fall victim to the ongoing dual citizenship crisis.
Last week, the senator said she did not believe she was a dual citizen. "I am proud of my Scottish ancestry and my father is too," she said at the time.
"I'm happy to put on record that I'm satisfied that my parents are both Australian citizens and I have no concerns about me being a dual citizen because of where they were born or came from."
Tasmanian Liberal Senator Eric Abetz said Senator Lambie had "acted with integrity" by resigning, and said she had brought some "interesting flare" to the chamber in her time.
Senator Lambie had promised to resign if she found she held UK citizenship, amid mounting pressure in the Senate on Monday.
Australian Conservatives leader Cory Bernardi hinted another Senate colleague could be in breach of the constitution.
"I do have concerns that there is a member of this chamber, at least one, who knows they are not eligible to be here because of their constitutionality," Senator Bernardi told the chamber.
If she resigns, Ms Lambie will end almost four years in the Upper House and break up the historic Indigenous caucus that has seen the most representation of Aboriginal and Torres Strait Islander people in the Parliament.
Ms Lambie said despite identifying as an Indigenous Australian, on her mother's side, Ms Lambie said she respects the law of the Constitution.
"That's the Constitution, that's the way it is... I stand by that, I respect that, and bottom line I should've probably been a bit smarter," she told ABC Radio in Tasmania.
Her Indigenous heritage has been plagued with doubt, Ms Lambie surprised many when during her maiden speech she claimed she was a descendant of Aboriginal leader, Mannalargenna.
"I acknowledge and pay my respects to Australia's Aboriginal Traditional Owners. I share their blood, culture and history through my mother's, Sue Lambie's, family. We trace our history over six generations to [the] celebrated Aboriginal chieftain of the Tasmania east coast, Mannalargenna," she said.
Ms Lambie is expected to be replaced by Devonport Mayor, Steve Martin, who was next on the Jacqui Lambie Network ticket at the 2016 election.
Ms Lambie said she has ruled out running in the upcoming Tasmanian election, she said she may consider another shot at federal politics and consider running the seat of Braddon if Labor MP Justine Keay is forced to resign over her citizenship.
Labor and the government have agreed that all MPs must provide their date of birth, citizenship at birth and details of when they were naturalised if they were born overseas by December 1.