MAYO MP Rebekha Sharkie is the latest politician caught up in the citizenship crisis engulfing the Federal Parliament.

The Nick Xenophon Team's only Lower House MP is facing questions over whether she renounced her UK dual citizenship in time to be eligible to sit in Parliament.

She said she believed she was in the clear and would make a public statement once she had finalised legal advice.

Ms Sharkie, who was born in England and moved to Australia when she was two years old, has previously stated she was in the clear.

In July she Tweeted: "For the record I'm Australian. Made sure my dual UK citizenship renounced BEFORE election #true-blue"

But she told The Advertiser on Thursday that the letter confirming she had renounced was dated June 29 - three days prior to the 2016 Federal Election.

Nominations, however, closed on June 9 and early voting had already begun.

Sydney university constitutional law expert Professor Anne Twomey said it was unclear if the High Court would disqualify MPs who received confirmation that they had ceased to be foreign citizens after the close of nominations after an election.

NXT Member for Mayo Rebekha Sharkie and Nick Xenophon Team leader Senator Nick Xenophon
NXT Member for Mayo Rebekha Sharkie and Nick Xenophon Team leader Senator Nick Xenophon AAP Image/Mick Tsikas

Ms Sharkie said she sent a letter to the UK Home Office on April 19 but did not get the letter confirming it had been renounced until about July 4.

"There are two views that you can take. One is that as long as you've taken all the reasonable steps yourself, that should be enough,'' Professor Twomey said.

Turnbull gets fired up over dual citizenship crisis
"You shouldn't be beholden to how long it takes for some bureaucrat in another country to process it. That's a reasonable view to take."

"On the other hand, you could take the view that the High Court has said if you are a dual citizen at the time of nomination, then that's it - you're disqualified."

NXT leader Nick Xenophon was himself drawn into the citizenship crisis, but was cleared by the High Court along with Liberal MP Matt Canavan.

Before the decision, Mr Xenophon announced he would quit the Senate to run for South Australia's lower house in the seat of Hartley.

April 19 2016 - Rebekha Sharkie sends paperwork to renounce British citizenship

June 9 - Candidate nominations for 2016 election closed

June 14 - Early voting commenced

July 2 - Election day

About July 4 - Received confirmation she ceased to be a British citizen on June 29