Just days after a strike was notified at its massive iron ore export hub, BHP has been forced to bargain a landmark union deal at a major coal terminal.

The unions claim their hand was forced by BHP’s ‘US-style’ stonewalling tactics during pay negotiations for its workers.

About 250 BHP workers will down tools at Port Hedland next week in the Pilbara’s first strike in decades and potentially costing mining giant BHP $100 million a day.