The Australian Mines and Metals Association has accused the CFMEU and other unions of scaremongering over foreign workers.
In a statement yesterday AMMA CEO Steve Knott said it was time to "put an end to the many misleading and inaccurate arguments about the use of skilled migrants".
"We are concerned that at the first mention of EMAs (enterprise migration agreements) or similar skilled migration programs, it has become commonplace for unions to roll out the same old campaigns of negativity and self-interested public fear mongering, complete with recurring misinformation," he said.
"The EMA concept was never about replacing Australian jobs with migrants."
"EMA's are only available to mega resource projects with a capital expenditure of $2 billion or more and with a peak workforce of more than 1500 workers."
"These high thresholds of capital value and employee numbers demonstrate that the very nature of EMAs is to be a last resort for a handful of our biggest projects only."
Knott said employers using EMAs had to have training programs in place for Australian workers, and Gina Rinehart's Roy Hill project has committed $20 million and 2,000 training positions.
But Dave Noonan from the Construction, Forestry, Mining, and Energy Union told the ABC while Roy Hill would import a maximum 1,700 foreign workers under its EMA, it might bring even more international labour in under 457 visas.
"… our understanding is that 1,700 provides a limit only in respect of the non-trades, and that at the trades and above level there is capacity to bring in more workers on 457s," he said.
The CFMEU said the Government and industry had not yet ruled out using this arrangement.
In a statement AMMA said the mining industry did not often use 457 visas and the sector was the fifth largest 457 user in Australia.
"Employers in the industry are focused on up-skilling and supplementing their Australian workforce, rather than replacing it," he said.