Steve Martin, who was number two on Ms Lambie's Senate ticket at the 2016 election, told Fairfax Media he believed the court may choose to immediately examine his constitutional eligibility when it meets on December 8 to select Ms Lambie's replacement.

This occurred with failed Senate candidate Hollie Hughes, who was set to replace Fiona Nash but was also ruled ineligible.

Mr Martin, too, faces a potential constitutional hazard that could put him in conflict with section 44 (iv) – whether, as a mayor, he holds an "office of profit under the Crown".

But if the High Court does not examine the constitutional issue Mr Martin faces, he said the Parliament should move to refer him to the court, so a clear legal position can finally be established.

Mr Martin said he had advice from the former Clerk of the Senate, Rosemary Laing, and her successor Richard Pye, that he was on safe legal ground.

However, he acknowledged that other constitutional experts such as professors Anne Twomey and George Williams said he could be ineligible.

"I am hoping the government refers me to the High Court. We need a judgement on this so it isn't murky any more. Let's get it done now, this is important," he said.

"Let's get this tidied up, I'm either in or I'm out."

He added: "if I'm ineligible that means I'm under an office of profit, so where is my super, sick leave and holiday pay [from his job as Mayor]?"

Mayors are typically paid an allowance, rather than a salary. Mr Martin suggested that if the job of a Mayor was judged to be an office of profit under the Crown, thousands of mayors and aldermen across the country could be eligible for billions in back-paid entitlements.

Asked if Ms Lambie, who resigned this week after discovering she was a British citizen by descent, could replace him if he was ineligible, Mr Martin said he was not sure.

The third person on Ms Lambie's Senate ticket, Robert Waterman, has indicated he does not want the seat – which could create a casual vacancy for Ms Lambie.