Nissan has warned that its UK car manufacturing plant in Sunderland may prove "unsustainable" if Brexit brings an end to the current tariff-free access to the EU. The Japanese company's global chief operating head, Ashwani Gupta, also told the BBC that any plans for Alliance partner Renault to take up spare capacity at the plant – the UK's largest car manufacturing facility – would be a matter for the French carmaker. News of the uncertainty will be on concern to the Sunderland plant's 7,000 workers who felt their jobs were safe after Nissan's restructuring plan, announced last week, appeared to signal a long-term future for its UK operation. Nissan announced plans to close its Barcelona site in a move which could cost €1.5 billion (£1.3bn) as it moves towards consolidation of its manufacturing operations amid reduced consumer demand.