The future of Nissan’s Sunderland factory remains in doubt amid the ongoing trade negotiations between the UK and the European Union, the car-maker’s European chairman said today.

Britain has until the end of the year to reach a free-trade agreement with the EU. If it fails, a 10 per cent tariff would be applied to cars and parts that could spell the end for many auto plants in the UK.

Read more: Nissan records losses amid backdrop of Carlos Ghosn scandal

“We would not be viable,” said Nissan Europe chairman Gianluca de Ficchy at a press conference in Paris, according to Bloomberg. “We just wouldn’t be able to sell our cars.”

The Brexit negotiations pose a problem for Nissan during a tough time for the Japanese car company. This month, it cut its full-year profit outlook and scrapped its year-end dividend amid tough trading conditions.

De Ficchy said that he hopes Nissan can stay in the UK so as to avoid upheaval to its business model during an uncertain time. “My working hypothesis is to stay in Europe with a factory in England,” he said.

Yet he raised the possibility that if the outcome of Brexit negotiations does not suit Nissan, it could make the Qashqai, Juke and electric Leaf models – which are currently made in Sunderland – at its partner Renault’s plants.

However, the Financial Times reported earlier this month that Nissan could double down on the UK if Brexit led to car tariffs.

If top European car-makers such as Volskwagen faced tariffs when they imported to the UK, Nissan could sell its cars more cheaply to British customers and potentially steal market share.

At the time, however, Nissan Europe denied any such plans exist, stoking uncertainty around the car-producer’s presence in Britain when the Brexit transition period ends in 2021.