Nissan boss Carlos Ghosn has said the company’s future investment in its Sunderland plant depends on the negotiations surrounding Brexit.

The BBC reported Ghosn’s comments, as well as his warning that Nissan’s continued investment would be put at risk by the vote to leave the EU.

The Sunderland plant employs 6,700 people and manufactures half a million cars per year. Nissan claims it is the biggest car factory in the UK.

At the start of the year, Nissan invested 26.5 million pounds in the battery manufacturing part of its Sunderland operations to continue Nissan EV production at the plant, as well as ramping up production of the Qashqai, which is also built in Sunderland.

Ghosn remained diplomatic, despite having favoured the UK staying in the EU ahead of the referendum on 23 June. He said “We are reasonably optimistic at the end of the day common sense will prevail from both sides.”

He continued to say Nissan’s level of investment in the UK depended on the agreement reached between the UK and the EU over customs and trade, although he was clear that prices of European-built cars will rise in the UK as sterling weakens post-Brexit.

Nissan’s market share has dropped in 2016. Its 5.15% decline represents 0.5% of total UK car registrations. Despite the Brexit vote, Nissan’s sales were buoyant in July, with a minor increase over the same month in 2015.

Nissan partner Renault, on the other hand, had a bad July, with a 31% reduction in July sales compared with July 2015, despite an overall year-to-date market share growth of 14.2% over 2015.

Vauxhall’s future in the UK has also been called into questions following the EU referendum, sparking fears that the UK’s prolific car manufacturing industry may suffer as a result of the vote.