A THREATENED strike at a car components factory could hit production at Nissan, unions have warned.

Workers at Unipres, which employs 770 people in Washington, Wearside, are being balloted for industrial action over Saturday working.

Trade union Amicus is claiming that, because Unipres supplies Nissan and Honda with body parts, any industrial action could have an impact on production at the car maker.

Unipres told the workforce in the summer it planned to close the plant on seven Fridays and bring the company in line with Nissan's working patterns.

This, the union said, would require workers to repay the time by working a minimum of six Saturdays a year.

The result of a ballot for industrial action among Amicus' 257 members at the plant will be known on January 18.

Carol McFarlane, Amicus regional officer, said: "Absolutely no attempt has been made to negotiate with staff or to reach a compromise deal and, unless they backtrack, the result will be damaging industrial action which will harm the company and have a very serious knock-on effect for the companies it supplies."

Amicus said the company had refused to negotiate about the changes or involve conciliation service Acas.

Unipres said it had consulted workers about the changes.

Graham Baines, general manager of finance and administration at Unipres, said he was shocked and surprised by Amicus' comments, and said the publicity was damaging to Unipres and the job security of its employees.

He said: "Employees have always been required to work a reasonable amount of overtime, a high proportion of which is on Saturdays. This has not changed. The company has been consulting with employee representives since July 2005.

"As part of this process, we made a number of improvements and concessions to the system on the request of employees. We reached a position where the employee representatives and unions were able to recommended the deal to the workforce.

"The system was introduced in November 2005."