WesTrac blamed a downturn in the mining industry for the sacking of more than half of its workforce.
The redundancies were announced by the earth-moving company on Thursday and union members met employees early on Friday to discuss the impact of the mass sackings.
AMWU state secretary Steve McCartney said WesTrac management had been concerned about job security since the most recent workplace agreements were signed.
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READ NOW‘WesTrac management told employees that if they took a lower pay increase there would be job security as a trade-off. Just a few months later they got the sack,’ he said.
He said workers had signed those agreements in good faith.
Mr McCartney said WesTrac employed overseas workers on 457 visas but ‘with the recent downturn in employment opportunities, it’s clear the case for temporary overseas labour is becoming more tenuous each day’.
WesTrac is owned by Seven Group.
The union said 11 people from WesTrac’s back office and another 40 workers from finance, accounting, IT and human resources were made redundant.