The terms of a Brexit deal that U.K. manages to strike with the European Union on customs, trade and free movement of goods would decide the future investment decisions about Britain’s biggest car plant, said the chief executive of Japanese carmaker Nissan.

Nissan’s Sunderland plant in the north of England has been lauded as one of Europe’s most efficient facilities, where it builds the popular Qashqai sport utility vehicle and last year the factory churned up nearly one in three of Britain’s 1.6 million cars that were sold.

Nissan and other companies were waiting to see the outcome of Brexit talks before making new investment decisions, Renault-Nissan Alliance Chief Executive Carlos Ghosn told the BBC, since most of the site’s output is exported to other countries in Europe.

“The question is what’s going to happen in terms of customs, what’s going to happen in terms of trade, what’s going to happen in terms of circulation, particularly of the products. All of these are very sensitive elements that are going to determine, how and how much we are going to invest in the UK particularly for the European market,” he said.

“Most of the production out of Sunderland is exported to Europe. So obviously for us the relationship which is going to prevail between the UK and Europe is very important … So you’re going to see a period where most companies are going to be waiting to see what’s going to be the new status,” Ghosn said.

In the wake of the June 23 referendum, faltering confidence in the British economy has been reflected by most business according to business surveys and manufacturing data. On Thursday, billions of stimuli were unleashed and rate was cut by the Bank of England.

Many firms are now closely watching formal talks on Britain’s divorce terms from the European Union and Nissan, which has invested around 4 billion pounds in its British manufacturing base, is one of them. The talks are unlikely to start until next year.

Any delay in the investment plans in the coming months could hit output and jobs in years to come since investment decisions in the car industry often occur several years before a model rolls off a production line.

Beginning a renaissance in the British car industry, which is forecast to hit record production levels by the end of the decade, British Prime Minister Margaret Thatcher signed a deal in 1984 to bring Nissan to the deprived north of England.

But ignoring their bosses who made the business case for remaining in the 28-member bloc, over 61 percent of voters backed Brexit in Sunderland which was potentially spurred on by concerns around immigration.

He was confident that British and European politicians would strike an amicable trade deal, said Ghosn but added that Sunderland was a “European plant”.

“We are reasonably optimistic that at the end of the day common sense is going to prevail from both sides,” he said.

More than 6,700 car workers are employed at the plant in Sunderland by Nissan. Less than 24 hours ago since the boss of Nissan had issued this warning, new car sales figures showed that amid uncertainty following the EU referendum, the previous strong growth in car sales had had come to an abrupt halt in July.

(Adapted from Reuters & The Guardian)