Jobs lost at Caterpillar site in Peterlee
Around 300 temporary workers are to lose their jobs at the Caterpillar truck production plant in County Durham.
The agency staff will finish at the Peterlee plant on Friday and will be paid one extra week's wages.
Caterpillar said the decision was taken because of the current trading position.
The announcement comes after 70 agency workers were released at the end of last month.
A Caterpillar spokesman said: "Caterpillar Peterlee is releasing approximately 300 temporary workers employed by Randstad, who previously performed roles throughout the factory.
"This is in addition to the 70 temporary workers released at the end of August.
"We regret the need to take this action but we need to align our workforce with demand and continue to position our business to be successful in the long-term."
Unite representative Rennie Simpson said: "The proposed work that we thought we had hasn't materialised."
More than 1,000 staff will remain at the plant.
The firm has other north-east bases in Stockton and Skinningrove.