Forrest fights 'evil' impost

Mr Forrest's company, Fortescue Metals, was rocked by the resignation of its external and government affairs boss, Deidre Willmott. The circumstances of the departure remain unclear but Ms Willmott's move continues a period of high turnover within the top ranks of the iron ore exporter.

Among the scores of workers sacked by Fortescue during a sudden debt crisis in September were external relations executives such as Julian Tapp and Rod Campbell.

Ms Willmott is known in Melbourne for her time as a top executive in the organising committee of the 2006 Commonwealth Games.

In Perth, she is better known for her Liberal Party connections, having been preselected for the seat of Cottesloe only to stand down when the West Australian Premier, Colin Barnett, who was then in opposition, reversed his retirement plans.

Ms Willmott has joined corporate advisory firm Cannings Purple as executive chairman.

Her departure came on the day that Mr Forrest told ABC radio his High Court challenge against the mining tax was about conquering evil.

Sampling from the proverbs of Irish philosopher Edmund Burke, Mr Forrest said evil would triumph when good people do nothing.

"We've decided not to do nothing," he said.

Mr Forrest also defended Fortescue's recent unsuccessful attempt to have more than $200 million in royalty payments to the West Australian government deferred, saying that the bid was logical.

Mr Forrest said the deferral was sought to ensure that expansion works at the Kings iron ore project could resume, after a dip in the iron ore price to $US90 ($87) per tonne during September halted work on the project.

Mr Forrest said the WA government would have much bigger economic benefits from the Kings project going ahead than from a single royalty payment and the deferral was designed to ensure the expansion could continue if iron ore prices stayed around $US90 per tonne.

But Mr Forrest said the request became redundant when the iron ore price recovered to the current level around $US120 per tonne.

"We put that logic to the WA government," he said. "But with the iron ore price going from $US90 per tonne to $US120 per tonne, they said 'Guys, you can bring on Kings whenever you like'."

Fortescue shares fell 6? to $3.90.