Up to 100 workers at a Queensland coal mine have been told via text message that they no longer have jobs.
The contractors, employed by Thiess mainly as drivers and machinery operators at Peabody's Burton coking coal mine in central Queensland, received the SMS on Thursday.
The Construction Forestry Mining Energy Union of Queensland has accused Thiess of treating its workers like "sausages on the shelf at the butchers".
"We haven't seen this sort of nonsense since the darkest days of the Howard era," CFMEU district vice president Steve Pierce said.
Mr Pierce said some of the members who received the text - which included information about when their jobs would wind up - were already aware they were out of work.
But others were not, he said.
Thiess has since apologised for sending the text messages.
US coalminer Peabody Energy announced in early August its intention to slash output at its Burton mine, 150 kilometres south-west of Mackay.
The company said it would cut output from 2.5 million tons a year to just one million tons.
Thiess was contacted for comment.