Union bosses want more than the 6.5% pay increase over two years.

Union leaders said the action would start on 26 January at the company's plants in Solihull and Gaydon, in Warwickshire.

Employees are already carrying out a ban on overtime introduced at the beginning of 2004.

The action will affect more than 8,000 workers.

Dave Osborne, the Transport and General Workers' Union National Secretary, said the trade unions did not take a decision to strike lightly.

"In view of the company's reluctance to re-open negotiations it is felt that further action is necessary to bring them back to the negotiating table," he said.

"Between now and 26 January we hope that the company will reflect on the decision, and meet the trade unions with a view to reaching a negotiated settlement."

Union bosses want more than the 6.5% pay increase over two years offered by bosses.

Staff say the deal would leave them worse off than their colleagues at Jaguar - another Ford company.

Amicus national officer Duncan Simpson said it was a decision made with great reluctance.

"We're calling on the company to think again and come back to the negotiating table," he said.