The next generation of the Vauxhall Astra will be built at its Ellesmere Port car plant if a satisfactory Brexit deal is reached, its owners have said.
The PSA Group said it would also invest in the Rüsselsheim plant in Germany to manufacture Opel Astras from 2021.
It said the decision would be conditional on the New Vehicle Agreement, negotiated with Unite.
In a statement, it said the decision demonstrated “the continuous effort and commitment” of the group.
Currently the Vauxhall and Opel Astra are built in Ellesmere Port in Cheshire, which was opened in 1962, and in Gliwice, Poland.
It said the decision on the allocation to the Ellesmere Port plant “will be conditional on the final terms of the UK’s exit from the European Union and the acceptance of the New Vehicle Agreement, which has been negotiated with the Unite trade union”.
Vauxhall has previously said it faces falling sales and relatively high manufacturing costs at the Ellesmere Port plant, which employs about 1,100 people.
By BBC business correspondent Theo Leggett
The decision to build the new model at Ellesmere Port would help to safeguard the future of the Chester plant, which has been in doubt since PSA Group took control of Vauxhall in 2017.
The factory currently makes an older version of the Astra, but sales have been declining, and the number of people working there has almost halved since the takeover.
Under the plan, Ellesmere Port would be one of two factories which will begin building the new Astra in 2021.
However, PSA Group has made it clear the decision to build the car in the UK will depend on the terms of the UK’s future trading relationship with the EU.
Sources say the minimum the company is looking for is a commitment to frictionless trade after Brexit, and no-deal is not an option.
Car production has been falling in the UK over the past year, amid increasing pleas from the industry for a Brexit deal.
The UK’s automotive industry has received a series of blows in recent months, with Honda announcing it will close its Swindon plant in 2021 and Ford saying its Bridgend engine plant in south Wales will close in September 2020 with the loss of 1,700 jobs.
Japanese car producers, including Nissan, have said that Brexit uncertainty is not helping them “plan for the future”.
Earlier this year, Nissan opted to build the next X-Trail model in Japan, rather than in Sunderland.