On 28 March 2023, Palmer's Singapore-based company, Zeph Investments, filed a notice of arbitration, suing the Commonwealth of Australia for AUD$296 billion over the alleged loss of contractual entitlement, “moral damages” and “sovereign risk”, in relation to the iron ore project for which Palmer's company, Mineralogy, had already lost a lawsuit. McGowan responded to the claim saying, "Today we have seen the most deplorable act of greed in Australian history", and "Clive Palmer is the greediest man in Australian history". The Attorney-General, Mark Dreyfus, said that the Commonwealth will "vigorously defend" the suit.
