The workers are with the operating engineers, who have about 100 people at the site, according to Vale spokesman Bob Carter.
They have set up at the main gate and are keeping out 1,800 to 2,000 other tradespeople scheduled to come on shift.
“It’s an illegal wildcat strike,” Carter said. “We are currently preparing an application with the courts to keep them from preventing other workers coming on site.”
Carter said the company had received no notice whatsoever the workers were going to launch the protest.
He said the root cause of the strike was “unclear,” but reports suggest it is related to temporary foreign workers.
To date, the Vale site has been able to fill positions with workers from this province and across Canada, but workers from outside of Canada have been considered an option as the project moves to its peak construction employment later this summer.
The Long Harbour site currently employs between 4,200 and 4,300 people, Carter said.