As many as 600 workers on Darwin's $36 billion Inpex gas project have reportedly been stood down amid reports of a contract dispute between companies building the site.
Construction, Forestry, Mining and Energy Union (CFMEU) spokesman Josh Burling told the national broadcaster he received a phone call early on Wednesday from a Laing O'Rourke representative confirming the layoffs.
"They will be making about 650 direct employees from Laing O'Rouke and a further 200 employees from subcontractors to Laing O'Rourke redundant from the tanks project at Inpex," Burling said.
It is understood a further 200 subcontractors could also be affected.
Word of the reported layoffs comes as Prime Minister Malcolm Turnbull and members of his cabinet prepare to meet with east coast gas producers in Canberra to discuss energy security.
Northern Territory CFMEU organiser Josh Berlin told reporters in Darwin the news came out of the blue.
"I would imagine (the workers) are not handling it too well at all," he told reporters.
"They've go the to go home now and tell their wives, families, 'No more money coming in. We've got to find more work.'
"Work is scarce at the moment, especially in Darwin itself, so, no, a complete shock."