Western Australia’s Labor treasurer says the state’s mining giants have been able to improve wages and conditions of workers without unionisation in the Pilbara, in comments that threaten to open a rift with the federal government over the resources sector.

In the midst of a state election campaign where the WA government is working to differentiate itself from its federal counterparts, state Treasurer and Deputy Premier Rita Saffioti said WA had been able to balance company profitability with improved workplace conditions without union activity.