New Brexit trade rules covering electric vehicles could cost European manufacturers £3.75bn over the next three years, an industry body has said.
The rules are meant to ensure that EU-produced electric cars are largely made from locally sourced parts.
But manufacturers on both sides of the Channel say they are not ready.
The European Automobile Manufacturers Association (ACEA) also warned the measures could reduce output from EU factories by 480,000 vehicles.
And they said customers would pay the price.