Ms Nash informed the Senate on Thursday afternoon.

The Senator for New South Wales was born in Sydney in 1965. It's understood she is a British citizen by descent and was informed of that earlier this week.

As such, she may be a dual citizen, falling foul of the Australian constitution.

“On Monday, following the deputy prime minister’s statement regarding his citizenship, I sought advice of the UK Home Office on my citizenship status,” she told federal parliament.

“By Monday evening, I was advised that a caseworker at the UK Home Office was of the view that – on the basis of the limited facts that I had provided – I was a British citizen by descent through my Scottish-born father.

“I was not provided with any further information to support that view at that time,” she stated.

Section 44 of the constitution says that an Australian member of parliament cannot hold allegiance to another foreign power.

Senator Nash told the chamber just before it rose that she will not be quitting any of her ministerial responsibilities.

“On the basis of the Solicitor-General’s advice, the PM has indicated to me that he sees no reason for me to stand aside from my portfolio responsibilities,” she said.

She was elected in 2004 and has served in a variety of ministerial roles, including Rural Health, Regional Development, Local Government and Territories, and Assistant Minister for Health.

Senator Katy Gallagher, Manager of Opposition Business in the Senate, told SBS World News: “Senator Nash’s statement means the entire National Party leadership is now facing disqualification from the parliament.

“As Senator Nash admitted, she has known since Monday that she was a dual citizen, yet waited until one minute before the Senate rose for a two week break to inform the parliament. This is simply not good enough.

“Malcolm Turnbull needs to explain why he is holding Mr Joyce and now Senator Nash to a lesser standard than Matt Canavan and not requiring them to stand down.”