Vauxhall is cutting another 250 jobs at its Ellesmere Port car plant on top of the 400 jobs it announced in October.
The carmaker, now owned by France’s PSA Group – maker of Peugeot and Citroen – said it needed to “accelerate the recovery of plant productivity”.
The Ellesmere Port plant in Cheshire, which makes the Astra, is to move staff from two production shifts to one.
The company told the Unite union last Thursday that more voluntary redundancies were now needed.
Vauxhall said it would conduct a statutory 45-day workforce consultation, adding it was committed to minimising the impact of the proposed reductions.
The company also said it was committed to the Astra plant continuing at Ellesmere Port.
PSA has said previously that manufacturing costs at Ellesmere were higher than other “benchmark plants” in the group.
Vauxhall employs about 4,500 people in the UK, with about 1,800 at Ellesmere Port. The company also has a factory at Luton, which makes vans.
In August last year, PSA became Europe’s second biggest carmaker after Volkswagen when it completed the purchase of Vauxhall and German brand Opel from US car giant General Motors.