Sections of the UK car industry face extinction unless the UK stays in the EU customs union, the president of the CBI has said.
Paul Dreschler also said there was “zero evidence” that trade deals outside the EU would provide any economic benefit to Britain.
He blamed a “tidal wave of ideology” for the government’s Brexit approach.
But the government said it was “focused on delivering a Brexit that works for the whole of the UK”.
“If we do not have a customs union, there are sectors of manufacturing society in the UK which risk becoming extinct,” Mr Dreschler said.
“Be in no doubt, that is the reality.”
He told BBC Radio 4’s Today programme the car industry in particular would suffer unless we get “real frictionless trade”.
Brexit campaigner Prof Patrick Minford, of the Economists for Free Trade group, said the CBI was “the voice of the large industrial vested interests that oppose the competition and productivity growth that free trade under Brexit will bring, as well as the fall in consumer prices that goes with it”.
“It also opposes lighter regulation that enables small businesses to compete with the big CBI incumbents. Also it loves cheap unskilled EU labour instead of having to use and train UK workers.
“The CBI has a long history of opposing good economics: from monetarism, through union reform, to leaving the ERM. It even wanted us to join the euro.
“The outgoing president Dreschler is as wrong as so many of his predecessors.”
Professor Minford added: “Precisely what Brexit will do is remove the EU protectionism and excessive regulation that is holding back our economy, not just in trade but in bold innovation generally, in bio-technology, in AI, in energy, in finance and much else.
“The gains from our potential free trade agreements are well documented. Our calculations put them at 4% of GDP,” he said.
To read the BBC’s report in full, click here.