A coal mine in central Queensland is set to reopen four months after operations were suspended and 400 workers sacked.
Glencore says it has rehired 50 people for preparatory work at its Collinsville mine from January 28.
In August, 400 people lost their jobs when Glencore announced that it was moving to an owner-operator business model and re-engineering the mine to improve productivity.
The Collinsville community then began campaigning for the company to rehire locals, amid concerns that a fly-in, fly-out workforce would be used when operations resumed.
Glencore says many of the 50 start-up crew are from the mine's previous Thiess workforce or from local communities.
However, CFMEU president Stephen Smyth says Glencore's claim that many workers are locals is a "real con".
"What's local to us is employees who are people who live in Collinsville and work there," the union boss told AAP.
"Their definition of local is anyone in Queensland. "We would like Glencore to come clean on what they are doing."
Mr Smyth says he is aware of only three Collinsville residents being re-employed by Glencore. The town would go under unless many more locals were rehired, he said.
"It's turning into a ghost town," he said.
"They are just struggling out there, people are travelling three and four hours to get a job." But Glencore says it is honouring its "stated aim of utilising skills available locally".
More than 2300 had applied for the 50 positions, a spokesman said. He said the start-up crew includes 20 Glencore employees and 30 labour hire workers.
Mr Smyth says the union is concerned about the use of labour hire workers who can be hired one day and sacked the next.
Glencore says more workers will be recruited as production ramps up throughout 2014.