Labor MP Tony Burke cast a shadow of doubt over Gilmore MP Ann Sudmalis’ right to govern.

Tuesday morning, Mrs Sudmalis was one of two politicians embroiled in the federal parliament’s dual citizenship crisis.

On a radio program, Mr Burke implied the Liberal Party was not judicious enough in undertaking background checks of Mrs Sudmalis and Member for Chisholm Julia Banks.

“We are in a situation where I’ve explained exactly what the Labor party does,” he said via ABC Radio.

“We go through parents we go through grandparents and then a team of lawyers work with the candidates to make sure they have fulfilled the requirements of section 44. 

“When Christopher Pyne yesterday in the Parliament started throwing accusations across the chamber, you could see sitting behind him in the camera shot the members for Gilmore and the member for Chisholm and the colour draining away from their faces.”

Mr Burke was referring to Ms Sudmalis’ mother, who was born in England and immigrated to Australia in 1951.

It is understood that Mrs Sudmalis, by descent, is eligible for UK Citizenship which she has never renounced. 

The South Coast Register promptly contacted Mrs Sudmalis and her staffer for comment, and did not receive a response.

The South Coast Register has contacted the British Consulate to confirm Mrs Sudmalis citizenship status. 

The SMH reported Tuesday, Mrs Sudmalis was born in Australia in 1955, to an Australian father and a British mother.

Her mother, Valerie Pybus, came to Australia in 1951 and did not become an Australian citizen – and renounce her UK citizenship – until 1989.

Ms Sudmalis, elected to Federal Parliament in 2013, has never taken up UK citizenship but nor has she renounced her entitlement to it.

According to the UK Home Office guidelines on citizenship, a person is entitled to register for citizenship through their mother if they were born before January 1, 1983; they would have become a citizen of the United Kingdom and Colonies by descent if women had been able to pass on citizenship to their children in the same way as men at the time of their birth; and they have right of abode which they acquired because their mother was, at the time of their birth, a citizen of the United Kingdom and Colonies.

A person must also be of good character in the view of the UK Secretary of State.

Ms Sudmalis appears to have satisfied all of these criteria and – while it is likely she is not a UK citizen – her difficulties may arise under section 44, part (i) of the constitution.

That section states that a person is disqualified from standing for Parliament if they are "under any acknowledgment of allegiance, obedience, or adherence to a foreign power, or is a subject or a citizen or entitled to the rights or privileges of a subject or a citizen of a foreign power".

Constitutional scholar George Williams told Fairfax Media that Ms Sudmalis' case could also hinge on whether citizenship was automatically conferred on her, or whether she had applied for it.

This, he said, "depended on UK law and whether that nation regards her as a citizen".

"No one is certain about how broad ranging the definition of entitlement might be," Professor Williams said. "If it means what it suggests, what we have seen so far for section 44 is really just the tip of the iceberg because it would cover anyone who might be eligible to apply for citizenship."

Labor Manager of Opposition Business Tony Burke flagged on ABC radio on Tuesday morning that Ms Sudmalis may have an issue regarding her status.

"When Christopher Pyne yesterday in the Parliament started throwing accusations across the chamber, you could see sitting behind him in the camera shot the members for Gilmore [Ms Sudmalis] and the member for Chisholm [Julia Banks] and the colour draining away from their faces. I presume that the process [the vetting process Labor undertakes on candidates] that I've just described for the Labor Party are not processes that the Liberal Party, the National Party, the Greens or One Nation have," he said.

Ms Banks declared last month that she was in the clear and not a dual Greek-Australian citizen.

A spokeswoman for the British High Commission said "we can't comment on individual cases, nor can we speculate on who may be entitled to British citizenship".

Ms Sudmalis declined to comment.