James Ramsbotham, Chief Executive of the North East Chamber of Commerce, says companies like Nissan need to know whether the UK will remain in the EU.
The head of the Japanese car company, Carlos Ghosn, has claimed they would "reconsider" their position if the UK left the EU.
This would threaten jobs at Nissan's plant in Sunderland, which employs 6,500 people.
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Very windy and mild with rain at times
Emma Jesson brings you Sunday night's forecast