24/08/2017 12:29 PM AEST | Updated 24/08/2017 2:20 PM AEST

High Court To Hear Political Citizenship Cases In October

That means there will be quite a few more weeks of uncertainty.

Andrew Meares/Fairfax
'We are very, very confident that our members who have been caught up in this will be held by the court to be eligible to sit in the parliament.'

CANBERRA -- Three days in October have been set for the full bench of the High Court to hear the eligibility of at least five federal politicians, including the Deputy Prime Minister Barnaby Joyce, to sit in parliament.

That means there's at least seven weeks of uncertainty still to run regarding the make-up of the 45th parliament.

High Court Chief Justice Susan Kiefel has ruled the court will hear the S44 citizenship cases of Joyce, his Nationals colleague senator Matt Canavan, One Nation senator Malcolm Roberts, former Greens senators Scott Ludlam and Larissa Waters on October 10, 11 and 12.

There is no date for any final ruling on the cases.

It comes as the lawyer of senator Canavan reveals he and his mother Maria - as reported in the Australian - became Italian citizens in 1983 through an Italian court ruling, even though neither was born in Italy.

The admission blows out the water the senator's previous claim that his mother applied for Italian citizenship in 2005 without his knowledge.

Canavan's barrister, David Bennett, reportedly conceded that it was "irrelevant" that citizenship had been applied for later on his behalf.

This new twist is certain to be heard again as part of the October hearings, which Federal Attorney-General George Brandis has told reporters in Melbourne he had expected and regarded as "expedited".

"There is an obvious public urgency in relation to this matter to clarify the situation," Brandis said.

"And the Chief Justice, Chief Justice Kiefel, acceded to that the 10, 11th and 12th of October - given the court's calendar - are the soonest practicable dates given the multiplicity of parties before the court."

"And we look forward to the speedy resolution of the matter."

However, the Turnbull Government had been hoping the High Court could hear the cases more expediently. Through the Solicitor-General Stephen Donaghue QC, acting for the Commonwealth, it had urged the court to hear the matters in a fortnight's time.

It is expected the cases of Nationals senator Fiona Nash and independent senator Nick Xenophon will also be held in October. Both cases have not yet been officially referred to the High Court by the Senate.

All seven cases are not identical, but the High Court -- sitting has the Court of Disputed Returns -- is being asked to rule whether the federal parliamentarians have breached the Australian constitution by being dual citizens when they nominated for election.

Prime Minister Malcolm Turnbull remains confident, telling reporters in Ettamogah on Thursday: "I am sure the court will clarify how Section 44 operates. "

"But I have to say again, we are very, very confident that our members who have been caught up in this will be held by the court to be eligible to sit in the parliament and therefore eligible too ministers."

Opposition Leader Bill Shorten insists Nash and Joyce should step down from Cabinet roles, saying Matt Canavan set the example by immediately stepping down from his portfolios while the High Court determines his eligibility.

"It is an untenable, unsustainable situation for government ministers with a cloud over their eligibility to sit in their portfolios, making decisions, which if it's subsequently found out they weren't eligible to sit in the parliament, the decisions they made can be appealed," Shorten told reporters in Melbourne.

"This is incompetent and impeding the ability of the Australian Government to look after the Australian people."