Workers at Nissan's top-performing North-East plant are threatening to strike for the first time in the factory's 18-year-history.

Trade union Amicus has announced members would be balloted on action over plans to move 60 jobs in the purchasing department to Cranfield, Bedfordshire.

The strike ballot would be the first at Sunderland's Nissan factory - the world's most efficient car plant, which employs 4,500 people - since production began in 1986.

Davey Hall, Amicus North-East regional secretary, said: "As things stand, if the Nissan Purchasing department workers are not prepared to relocate some 240 miles south to Cranfield, they stand to lose their jobs, their redundancy pay, money in lieu of notice and, as they have not been offered any other alternative, ultimately their dignity."

The manufacturing union, which represents almost 800 workers at the plant, claims staff have not been consulted over the relocation plans and that the company refused to meet union officials.

Mr Hall said staff had been given until January to decide whether to "uproot their families or lose their jobs".

He added: "We feel that Nissan is being very silly and childish by trying to exclude Amicus officers from representing their members.

"Amicus has sole recognition with Nissan. Nissan's refusal to involve Amicus is viewed with absolute resentment by our members."

Staff will be issued with ballot papers on Monday and the result of the vote should be known on December 8.

A statement from Nissan said last night that the company was in "very early discussions" about the move of 60 jobs, which would not take place until June.

"Any mention of a strike ballot is only from Amicus and is not only inappropriate, it's premature and an over-reaction," it said.

"It is not true that we have refused to hold talks with Amicus officials.

"We are talking with all representatives, including the Amicus shop stewards elected by the workforce and are at an early stage of discussions.

"In common with most companies, our union-backed procedure involves talking with regional officials only if local discussions cannot resolve the situation.

"There will be no loss of employment rights. These discussions are ongoing and we stand by our track record of fair and generous treatment of our employees.

The statement added that it had given workers incentives to move, with up to £7,500 of relocation allowance and six years' mortgage support.

Nissan said it was moving the purchasing department in order to achieve cost targets before a new vehicle is launched.

The Wearside plant was set a 2003 target of building 350,000 Micras, Primeras and Almeras, with some models exported back to Japan.