Carmaker Nissan will reconsider its investment strategy in Britain if it leaves the European Union, the company's chief executive Carlos Ghosn has told the BBC.
Ghosn was visiting Nissan's factory in Sunderland, northeast England, which employs 6,500 workers and will build the new Qashqai model.
Prime Minister David Cameron has promised a referendum on EU membership in 2017 if his Conservative Party wins the next general election in 2015.
Asked how Nissan would react if Britain were to leave the EU, Ghosn said: "Obviously it's going to be a major factor happening and we are going to need to consider what does it mean for us for the future.
"If anything has to change, we (would) need to reconsider our strategy and our investments for the future."
But Ghosn said he considered the exit scenario to be unlikely.
British industry is divided about the merits of EU membership.
The employers' association, the Confederation of British Industry (CBI), said in a study this week that membership of the bloc is "overwhelmingly" in Britain's economic interests.
But on Thursday, a former head of the CBI, Digby Jones, said Britain must be ready to leave the EU to boost its competitiveness in the open market.
Writing in The Times, he said the EU was a "job destroyer" and that leaving would not be an "unattractive option".