The West Australian government is facing another lawsuit from Clive Palmer, with the Queensland businessman suing the state for “unconscionable conduct”.

Mr Palmer’s latest claim is in addition to approximately $30 billion he is demanding as part of an iron ore dispute with the state government.

Mr Palmer said the latest claim, lodged in the Federal Court, would be served on the state within 21 days.

The claim relates to unprecedented legislation passed by WA’s Parliament, terminating separate action by Mr Palmer under arbitration.

Under that arbitration fight, Mr Palmer is seeking about $30 billion in damages, costs and interest over a decision to deny him approval to develop the Balmoral South iron ore project in the state’s Pilbara region.

Clive Palmer confident of court win

Mr Palmer said legislation would be “for nothing” because the High Court would deem it unconstitutional.

“The simple fact is the state of Western Australia does not have the power to control either the Federal or the High Court of Australia,” Mr Palmer said in a statement.

“The amount of damages is likely to exceed the damages claimed in arbitration the state had previously agreed to but legislated to terminate.

“Mineralogy’s action in the Federal Court will result in a greater amount of damages and the High Court of Australia will, in my view, find the act unconstitutional.”

Tweet from @CliveFPalmer

Long list of Clive Palmer lawsuits

WA is now fighting a flurry of lawsuits against Mr Palmer.

On Wednesday night, Mr Palmer launched a defamation case against WA Premier Mark McGowan in the Federal Court.

There is also a case in the Queensland Supreme Court, with WA fighting to overturn a previous ruling that the awards made in arbitration over the iron ore dispute should be “enforced”.

And, on top of this latest Federal Court action, Mr Palmer has repeatedly signalled he will challenge the validity of the legislation in the High Court.

Mr Palmer is also challenging WA’s interstate border closure in the High Court, with a decision expected later this year.

Mr McGowan dismissed the defamation case as a “personal legal fight”, saying he would not be distracted by it.

“I won’t take a backward step when it comes to protecting the interests of Western Australia,” Mr McGowan said.

“I will always stand up for WA.”

Mr Palmer has also launched an advertising blitz against the WA government, with a flurry of newspaper and radio commercials attacking the state’s handling of the iron ore dispute and the border closure.

-ABC