Clive Palmer's legal battle with the state of Western Australia continues to be fought on several fronts, with a defamation claim against Premier Mark McGowan set to intersect with another matter being heard in the High Court.
Mr Palmer in August filed a lawsuit against the premier, who lodged his own defamation counter-claim a month later.
The two parties appeared remotely via their lawyers in the Federal Court on Tuesday for a case management hearing, just days after the High Court struck out Mr Palmer's constitutional challenge to WA's COVID-19 hard border closures.
Mr Palmer's barrister Matthew Richardson told the court his client had filed writs in the High Court against the state of WA.
They relate to extraordinary legislation passed in WA's parliament in August to amend a 2002 state agreement with Mr Palmer's Mineralogy company and terminate arbitration between the two parties.
The bill is designed to block Mr Palmer from claiming damages from the state.
Mr Palmer is seeking almost $30 billion in damages over a decision by the former state government not to assess one of his mining projects.
A further hearing in the High Court matter is listed for November 16.
Mr Richardson said that case was likely to be heard in the first half of next year, and a loss for Mr Palmer could mean having to abandon aspects of his defence against the defamation counter-claim.
"They're not a huge part of the case ... but it is an issue that we have raised in defence to the claim brought by the premier," he told the court.
Mr McGowan's solicitor Carmel Galati flagged a challenge to many of the "contextual imputations" raised in Mr Palmer's defence.
"We don't think that the imputations are even arguably capable of arising," she said.
"The capacity for the cross-claim to basically hijack the rest of the proceedings is quite real."
Justice Richard White ordered both parties to provide further submissions, including on the potential for mediation, before returning on December 11.
Mr Palmer, via Mineralogy, is separately pursuing further damages from the WA government with a claim of "unconscionable conduct" in the Federal Court.
Mr McGowan has confirmed WA taxpayers will foot the bill for his private lawyer in the defamation case but any potential benefits would be returned.