UNION leaders are seeking urgent talks with Nissan managers after the company's chief executive Carlos Ghosn repeated warnings that the Sunderland plant could lose production of one of its most important cars if Britain remains outside the euro.

Mr Ghosn, speaking at the Detroit Motor Show said the replacement for the Almera would not automatically be built in Sunderland if sterling continued as an independent currency.

The company, which employs 4,500 workers at its flagship plant on Wearside, said last night that it was not the first time Mr Ghosn had warned of investment problems if Britain did not join the single currency.

But Amicus regional officer Mel Barras said: "We will be seeking a meeting with the company to clarify, on behalf of our members, the points that Mr Ghosn made in respect to the most productive car plant in Europe."

A Nissan Motor Manufacturing UK (NMUK) spokesman said last night: ''Mr Ghosn has been very consistent in what he has been saying in response to questions about the single currency issue.

''The UK's exclusion from the euro adds an element of unpredictability when having to make an investment decision."

Pro-euro lobby group Britain in Europe said the warning from Nissan was "yet another example of how Britain is paying a rising price for staying outside the euro''.

The campaign manager of the No Campaign against euro entry, Matthew McGregor, said: ''This is not the first time Carlos Ghosn has made these kinds of threats.

"In fact, the UK car industry is doing well outside the euro."