Production of electric and hybrid cars will not be introduced to Ellesmere Port until the outcome of Brexit is decided, Vauxhall's parent company has warned.
Carlos Tavares, chief of Groupe PSA, said that investment could not be ploughed into the Cheshire plant before the political situation becomes clearer.
Speaking to ITV News, Mr Tavares argued that the introduction of electric cars would represent a "very big" business decision for PSA.
He also offered his own opinion that a no-deal Brexit scenario would be a "disaster" for both Britain and continental Europe.
PSA, which is France's largest car manufacturer, includes Citroen, Opel and Peugeot among its brands.
Asked what was stopping the move to electric cars at Ellesmere Port, Mr Tavares said "basically Brexit".
"That represents a very big investment, as you may imagine, and we cannot invest in a site where we don't know what is going to be the profitability based on eventual customs duties that would be put on top of that business case," he said.
"So basically, those investments are now waiting for clarification on the Brexit outcome."
Pressed on what a no-deal outcome could mean for the port, Mr Tavares said: "What I want to say is that for the UK as a whole, not specifically for Ellesmere Port, a no-deal outcome I think it's a disaster.
"It's also a disaster for continental Europe. We Europeans have all the reasons in the world to make a deal.
"I'm not focused on one specific plan or another. I'm just saying that as a European citizen, as chairman of the European Automotive Association and the head of PSA, we want a deal."
Meanwhile, BMW has told ITV News it has also stepped up its warnings over a no-deal Brexit as its production in Cowley may be at risk.
Peter Schwarzenbauer, the BMW Board member responsible for Mini and Rolls Royce, said the firm may have to "reconsider" UK production if the company could not manage the extra costs in event of a no-deal Brexit.
He continued: "If there's no deal and tariffs are going up and this means an increase of costs for the Mini brand, that's definitely a challenge and we would have to look at it, if it really comes."
He said: "Whatever we see in costs increase on the Mini brand, it will trigger discussions in our company, what to do with the Mini brand.
"We are committed right now, but we would have to reconsider it," he added.