"What threatens Australian workers is the abuse of guest workers and the use of guest workers to drive down Australian workers' wages and conditions", Dave Noonan, national secretary of the construction division of the Construction Forestry Mining Energy Union (CFMEU) told 91̳ Weekly.
Speaking in opposition to the federal Labor government's scapegoating of refugees, Noonan said the real threat to workers' living standards came from the abuse of guest workers, particularly those given temporary visas under the 457 visa scheme.
He described the "outrageous" situation in which "some of the most vulnerable people coming to this country, refugees, are being demonised, when we're not having a debate about what we really should be doing for a balanced immigration policy in this country".
Noonan said: "There are things happening here that are undermining the security of working people that are being done under the radar, while we have a very ill-informed and divisive debate about refugees.
"People used to have the opportunity to come to this country and stay here. Big business seems to want — a situation where migrants fill the short-term needs of big business and are then repatriated home when they have finished with them or they start to demand their rights."
Noonan also expressed concern for the rights of many international students.
"We come across situations daily of the exploitation of those people", he said.
"Hysteria about refugees ignores that fact that there are 50,000 people overstaying tourist visas, on programs supported and sponsored by some of the largest employers in this country."
The CFMEU was "certainly not anti-immigration. We're a union of migrants.
"But we didn't used to have a system when people were thrown out as soon as big business was finished with them. People could come here and build a future."