About 900 workers were not paid about $1500 gross each after refusing to work for five days in May because of concerns about fly ash, which they said was carcinogenic.

The company refused to pay the workers, saying the walk-out was classed as industrial action.

Last week’s four-day hearing in Collie heard from a number of witnesses.

Management from IHI, HPT, EC and M, K and K Electrical, Essential Fire Industries, United Industries and Safe and Sound Scaffolders will give evidence in Perth in mid-November.

The IRC has set aside six days for the hearing in Perth.