Johannesburg - Cosatu will march against labour brokers at an Xstrata mine in North West, it said on Thursday.
"[The Congress of SA Trade Unions] is convening a march to Xstrata Elands mine where 250 workers who were employed by Grinaker have been expelled," it said in a statement.
The workers had embarked on a wildcat strike demanding better working conditions.
"Cosatu has learned that the mine has since terminated the contract of the service provider after the strike, leaving the workers unemployed."
It would march on Friday to demand that the workers be reinstated, to avoid mass action against the company.
Construction company Grinaker could not immediately comment, and Xstrata spokesman Chris Tsatsawane said he had not seen Cosatu's statement.