Video report by ITV News North of England Correspondent Damon Green
Employees in the Ellesmere Port community fear "uncertainty" over the future of their jobs as Peugeot-owner PSA prepares to buy the Vauxhall plant.
The Cheshire factory's 1,600 workers have been given assurances that their jobs will be safe until at least 2021.
But Vauxhall workers, and employees in the local area who rely on their trade, remain cautious over the future.
Speaking on his way into the factory at dawn today, one worker told ITV News: "It's obviously nervous times for everyone, but you've just got to stay hopeful, haven't you?"
Another added: "It's the uncertainty. Peugot have had their factories in Britain before and closed them so, who knows?"
Walking through the gates, another said: "It's been positive what we're hearing from the union and their business secretary, so I'm quite confident, quite happy."
But a less convinced worker quipped: "Just got a few months to learn French, haven't I?"
The £1.9 billion deal was announced in Paris on Monday and will see PSA become Europe's number two carmaker after Volkswagen.
Speaking in Ellesmere Port, John Cooper, from the Unite union, said: "It's the second largest, if not the largest, private employer in the region. If there was no Vauxhall Motors here, it would devastate the whole economy."
Donna Shone, who works in a cafe near to the plant, said her job relied on the business from Vauxhall workers.
She added: "I hope they secure it for all of the people of Ellesmere Port that work there. It's a massive part of Ellesmere Port - you'll find there's thousands of people that work there, and like you say, have got mortgages, families."
PSA are being joined by French bank BNP Paribas in the purchase of GM Financial's European operations through the formation of a 50%-50% joint venture and the deal is expected to be completed at the end of this year.
The former president of General Motors (GM) Europe told ITV News that the relatively high number of parts that need to be imported to the UK is what "puts these plants at risk".
Three quarters of the parts used to make the Astra are imported, putting Ellesmere Port at particular risk.
Nick Reilly, who spent 37 years at GM - the parent company of Vauxhall and Opel, 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."