Peugeot-maker PSA bought Opel and its British sister brand Vauxhall last year when it acquired General Motors’ loss-making European arm and has been pursuing a restructuring plan to return it to profitability.

The French automaker is cutting the workforce at Ellesmere Port by a third to make it more efficient, but the move has renewed workers’ fears about the future, with the company yet to decide about future production at the site.

Unions want the firm to commit to fresh investment this year but Peugeot said Brexit uncertainty is weighing on its decision-making.

"We can't make the world any easier for our workers and unions and staff than it is for us on the outside," PSA Europe boss Maxime Picat told Reuters at the Geneva Motor Show.

"When there's uncertainty, we cannot bring them certainty. We're going to have to wait for the political calendar," he said.

(Reporting by Laurence Frost and Gilles Guillaume; writing by Costas Pitas; editing by Stephen Addison)