Unions are "right to be worried" about the future of Vauxhall's UK car manufacturing plants, according to the former president of General Motors (GM) Europe.
Nick Reilly, who spent 37 years at GM - the parent company of Vauxhall and Opel, gave weight to the concerns voiced by worker's union Unite's following the sale of Vauxhall today.
He told ITV News Business Editor Joel Hills that any "commitment to the current model" made by buyer Peugeot's "is no commitment at all".
He said: "The unions are correct to worry about it. The UK is not in a good position when compared to other places for various reasons - not because of the efficiency of the plants."
He added: "Getting [the company] profitable by 2020 means they will have to either increase their sales or it means they are going to have to close a plant to take costs out...
"There is a risk they will have to close a plant."
Mr Reilly explained that the relatively high number of parts that need to be imported to the UK is what "puts these plants at risk".
When asked why Ellesmere Port, the Cheshire factory, could be at risk, Mr Reilly said: "The reason Ellesmere Port is vulnerable is not because of the plant itself or the people there. Actually, that plant is one of the most productive plants in the whole GM worldwide and they produce very high quality.
"The reason there is a risk there is that they have to import many components into this country in order to assemble the final car. There's not many components produced in this country. It's something we gave up in the 1990s and we have to get it back - and that's going to take everybody to make it happen, including the government."
Speaking about Brexit, Mr Reilly added that the timing of the deal could be problematic.
He said: "The uncertainty around how Brexit will come out - whether there'll be tariffs on cars in the future, for example - won't be known before the decision is taken.
"Brexit in itself should not be a problem, but the fact that there is so much uncertainty around it could be a risk."
He added: "The government can play a very important role in encouraging component manufacturers to come into this country and produce in this country."