The National Distribution Union is concerned the Feltex yarn plant in Dannevirke could be in danger of closing after a new call for voluntary redundancies.
The union says Godfrey Hirst, the Australian company which owns the plant, has told its 98 workers it needs to cut eight jobs and has asked for volunteers to take redundancy.
In March, 165 people lost their jobs when the company's Foxton and Fielding factories closed.
The union says the company has admitted it would consider accepting as many as 20 applications for voluntary redundancy.
That has sparked concern that Godfrey Hirst could shift production to another factory as demand for carpet shrinks.
