Malcolm Roberts will be grilled by government lawyers in the High Court over his eligibility to remain in parliament.
The solicitor-general will cross-examine the One Nation senator in Brisbane next Thursday about his knowledge and "state of mind" in relation to dual citizenship.
Lawyers for Senator Roberts will also seek to challenge expert evidence about the legality of the steps he took to renounce UK citizenship.
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British citizenship expert Laurie Fransman QC's appearance next week will be subject to availability, but Senator Roberts' legal team have requested two hours to question him.
"Goodness, you do have a lot to talk about," Chief Justice Susan Kiefel said on Friday.
They will also look to call their own expert on British law, barrister Adrian Berry, who often serves as a junior lawyer to the government's pick.
The High Court, sitting as the Court of Disputed Returns, heard their arguments would hinge on whether it was sufficient for Senator Roberts to send an email to renounce his British citizenship.
Also in question were the legal ramifications of Senator Roberts not paying the usual renunciation fee.
The experts have been told to discuss the contradictions in their interpretations.
"They shouldn't have to walk very far," Chief Justice Kiefel said.
Senator Roberts' team have been given until Tuesday to summarise the differences in a dot-point document.
The One Nation senator's sister has filed an affidavit to support his claims.
The court also heard the legal issues at play in the matters of Barnaby Joyce, Matt Canavan, Fiona Nash and Nick Xenophon were "materially indistinguishable".
Tony Windsor - the political nemesis of Barnaby Joyce - will act as "contradictor" in the deputy prime minister's case.
While the facts of each case differed, the law was the same.
All of them were born in Australia and insist they had no knowledge of acquiring foreign citizenship by descent.
The solicitor-general said it was "virtually inevitable" the cases would stand or fall together.
Former Greens senator Larissa Waters will submit she was disqualified, while the government will argue she was not.
Her former colleague Scott Ludlum is not expected to contest his eligibility.
