Unions say a decision to sack 95 coal miners at Collinsville in north Queensland is unnecessary and greedy.
Thiess and mine owner Xstrata have been reviewing the mine's operations, north-west of Mackay, in view of the downturn in the price of the commodity.
Thiess says it is examining all options to retain staff and will try to find other jobs for those workers.
However, a Thiess spokesman says a reduction in the mine fleet has made redundancies unavoidable, with a total of 95 positions to go by the end of January.
Construction, Forestry, Mining and Energy Union (CFMEU) spokesman Steve Pierce says Xstrata and other mining companies are exaggerating the severity of the downturn in export coal prices to justify job cuts.
"They're saying that the market is shot, the industry is dead," he said.
"Well, they are still making in excess of $100 a tonne for coal that three or four years ago were getting $40 and $50 a tonne for, so they are still making damn good profits.
"We need to dispel the myths that is being perpetrated by the coal industry that they are going broke." He says it is pure greed and short-term thinking.
"It is really a mercenary decision in our view by Xstrata to protect their profits," he said.
"Unfortunately coal companies do this every time there is a slight hiccup in the market.
"They will terminate these people, then in 12 months' time they will be whinging and moaning in the press saying that there are no skilled operators available to go to their mines to help them meet the demands.
"Are we going to see more of it? "I think from multinationals like Xstrata, Rio Tinto, BHP there is always the possibility that when there is a dip in profits - the board rooms there - first thing they will do is rally around and protect themselves and profits.
"Unfortunately when they do that usually the first workers that are hurtare the workers at the coal face."