Speaking at the Sunderland plant where the new model of the Juke will soon start production, he said the Japanese car giant had worked through business scenarios associated with Brexit.
But he said Nissan could not manage the uncertainty which they face when trying to plan for the future.
Two thirds of the components for the new model come from the EU and 70% of production was aimed at the Continent.
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Mr de Ficchy said: "If we are in a situation in which tomorrow we have to apply 10% export duties to 70% of our sales, the entire business model for Nissan Europe will be in jeopardy."
Mr de Ficchy said he had no specific message for the Prime Minister, but said business currently had no clear understanding of the "future evolution of the Brexit decision".
Mr de Ficchy said the decision to end night shifts at the Sunderland plant was not linked to Brexit but was aimed at optimising the two production lines for the models built there, including the new Juke.
He said the workforce at Sunderland was an asset to be preserved, with a successful history of producing 10 million "high quality" vehicles.
"We know the workforce is concerned about that situation (Brexit) - we are also concerned. That's the reason we are here - to express our concerns."