Vehicle manufacturers have called for “realism” after a EU legislators backed a plan on Wednesday to cut carbon dioxide emissions by 40% in 2030.
The European trade body ACEA fears the short timescale would increase costs for consumers and hurt auto sector employment.
It had lobbied for a 20% CO2 reduction by the same deadline.
Erik Jonnaert, secretary general of ACEA, said: "It would essentially force the industry into a dramatic transformation in record time."
"The vote risks having a very negative impact on jobs across the automotive value chain," he said.
"We can only hope that national governments bring some realism to the table when adopting their common position on the future CO2 targets next week," Jonnaert said.
European Parliament members voted for the 40% cut on Wednesday, as a compromise between the parliament's environment committee’s desire for 45% and the European Commission’s recommendation of a 30% reduction.
"If the EU wants to lower CO2 emissions, fine. But electric vehicles are like organic food -- they are more expensive, and Asia has a monopoly on (battery) technology. Let's be honest," PSA Group CEO Carlos Tavares, who is president of ACEA, told French media at the Paris Motor Show.
BMW Group chief executive Harald Krueger has claimed a 30% cut was the "maximum stretch" the industry could manage, and Renault boss Carlos Ghosn warned the “question is what's going to be the cost” for carmakers and ultimately for consumers.