Toyota Motor Europe chief Johan van Zyl has said a Brexit without a deal would affect the firm's investment decisions.
The UK is on course to leave the European Union in March next year, but the two sides have yet to strike a deal.
Mr van Zyl told the BBC if the firm is unable to sell into the EU market duty free, it will harm its UK operations.
Many carmakers in Britain have warned a bad or no Brexit deal would be damaging for the UK car industry.
"If we have anything that has an impact on your competitiveness of manufacturing in the UK, it will definitely have an impact on future investment decisions," Mr van Zyl said in response to a question about a "no-deal" Brexit scenario.
"The reason for many manufacturers being in the UK is the fact that they could export to the European market duty free - and that is a critical one," he told the BBC on the sidelines of the Paris Motor Show.
Toyota UK has said that a no-deal Brexit would temporarily halt output at its plant in Burnaston - which produced nearly 150,000 cars last year, 90% for export to the European Union.
The Burnaston plant produces the Auris and the Avensis. Toyota is investing £240m there to enable the production of the new Corolla from the end of this year.
Toyota UK has said that a no-deal Brexit would temporarily halt output at its plant in Burnaston - which produced nearly 150,000 cars last year, 90% for export to the European Union.
The Burnaston plant produces the Auris and the Avensis. Toyota is investing £240m there to enable the production of the new Corolla from the end of this year.
Asked about the Burnaston plant's future, Mr van Zyl said Toyota had made the investment because they "trust our people" but that a "very bad" deal would impact investment decisions.
"The UK market in itself is not big enough to justify a plant that size," he said. "If we cannot sell into the European market, it will have an impact on the future of our plant."
Toyota also has an engine plant in Deeside. The site opened in 1992 and employs 620 people.
source: BBC News