Jacqui Lambie has made an emotional farewell to the Senate after discovering this morning she is "not as bloody Australian as they come".

Key points: Senator asked UK Home Office this week to check her status and received confirmation early yesterday morning she obtained British citizenship through her Scottish father

Senator asked UK Home Office this week to check her status and received confirmation early yesterday morning she obtained British citizenship through her Scottish father Ruled out running in the upcoming Tasmanian election, but left open option for another tilt at federal politics

Ruled out running in the upcoming Tasmanian election, but left open option for another tilt at federal politics Farewell prompts unusually emotional scenes in the Senate

The Tasmanian senator confirmed the UK Home Office had told her she was entitled to British citizenship by descent because her father was born in Scotland.

"It is with great regret that I have to inform you that I had been found ineligible by way of dual citizenship," she told her Senate colleagues this afternoon.

"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.

"It is not because of him that I am leaving this place. It is because of him that I am here in the first place."

Ms Lambie said she had asked her father to answer one question: "Am I gone?"

"He said, 'Yes sweetie, you're gone. I think we're gone," she said.

The Tasmanian firebrand, a former member of the Australian Defence Force who has spoken publicly about her son's battle with ice addiction, said she had worked hard to be a voice for "those who don't often get much of a voice in this chamber".

"Unlike some in this place, who say they are there for the battler, I actually refused to deliver the budget into surplus by driving struggling families into further poverty," she said.

After her speech, the outgoing senator took several minutes to hug each of her colleagues who came forward to say goodbye, in scenes that were unusually emotional for the chamber.

Jacqui Lambie was embraced by senators from all sides of the chamber. ( ABC News: Jed Cooper )

Attorney-General George Brandis thanked Ms Lambie for the passion she had brought to the parliament.

"It will be obvious to you, Senator Lambie, from the spontaneous expression of affection and, may I say, love that has come from all sides of this chamber, the effect that you have had upon all of the colleagues who have served with you since you have been elected," he said.

"The Senate brings together people from all parts of Australia, from all walks of life, from all political philosophies, from all backgrounds, and it is the richer for it.

"The Senate has been the richer for your membership of it."

Lambie shocked to discover dual citizenship

Sorry, this video has expired Senator Patrick Dodson farewells Jacqui Lambie

Ms Lambie had previously released a statement saying she was satisfied her parents were both Australian citizens.

But this morning she told a Launceston radio station she realised she may have had a problem while going back over her father's history following the resignation of Stephen Parry from the Senate.

"When Stephen Parry came out and mentioned a boat and a date, I'm obviously doing my autobiography, I've gone back over Dad's stuff and straight away I just thought, 'Oh my God'," she said.

The senator asked the UK Home Office for clarification of her status on Monday and said the confirmation came back early yesterday morning.

Ms Lambie said she always knew her father was born in Scotland, but was satisfied both her parents were Australian citizens.

She said she never questioned her father's assurances that she was not a dual citizen until other federal politicians began to fall.

"My dad said, 'You're as Australian as they bloody come'," she said.

"Well, you know, apparently we're not as Australian as they bloody come.

"When you run it past your dad and he's sitting there saying 'we're not bloody dual citizens, you've got Indigenous, you've served, your grandfather's served', until you start hearing what's been going on … you just don't [expect it]. Your head's not even there."

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In her maiden speech, Ms Lambie told the chamber she was related to, if not descended from, a prominent Aboriginal resistance leader of north-eastern Tasmania.

She joined the Federal Parliament in 2014 as part of Clive Palmer's party, and quit later that year to start her own party.

"I think because I was with Palmer United Party I would have thought, 'OK, well if there's going to be any questions they would have checked all this'," Ms Lambie said.

The senator was audibly upset during her interviews, describing her shock when she realised she had a problem.

"I don't know who feels worse — me or my dad. I think we're both gutted. We're not sharing love for the bagpipes this morning I can tell you," she said.

Asked whether she agreed with the section of the constitution that forbade dual citizens from serving the Parliament, Ms Lambie said: "I didn't write that but I stand by that, I respect that. Bottom line, I probably should have been a bit smarter and checked that citizenship stuff."

What next for Jacqui Lambie?

Ms Lambie has ruled out running in the upcoming Tasmanian election, but left open the option of another tilt at federal politics.

"I have no interest in state politics — I can't get the deals in state politics like I can get up here [in Canberra]," she said.

"I have got candidates running out there for the state election. I'm going to put on my Jacqui Lambie Network jacket and I'll be right beside them."

She also ruled out asking her replacement to take up the Senate position and then resign, allowing her to make an immediate return to the Senate.

The next JLN candidate on the Tasmanian Senate ticket is current Devonport Mayor Steve Martin.

"I would never do that to Steven. I would never ask him to do that, that is not the correct moral thing to do. It is now his position," she said.

Ms Lambie said she was considering all other options open to her, including a possible run in the seat of Braddon if Labor MP Justine Keay is forced to resign over her citizenship.

"I think if I stop I'll just roll into a ball and I just don't want to," Ms Lambie said.

"Every seat's an option. I'd like to spend a bit of time with Andrew Wilkie, obviously he can probably read better what the numbers are going to be after the next election."

Ms Keay did not receive confirmation that her British citizenship had been renounced until after the cut-off date for nominations for the federal election, which is the date required by section 44 of the constitution.