Workers at General Motors Europe's Ellesmere Port plant in Britain walked off the job on Thursday after the company proposed cutting nearly 1,000 jobs at the factory, unions said.
A Transport & General Workers Union (T&G) spokesman said workers staged a "spontaneous walkout" earlier on Thursday, halting operations at the site in north-west England.
The T&G and Amicus unions blamed the walkout on comments by GM Europe President Carl-Peter Forster on Wednesday that the company had proposed cutting nearly 1,000 jobs at the plant to streamline production of the Opel/Vauxhall Astra model.
"Britain is the soft touch of Europe when it comes to taking away workers' jobs. That's why Vauxhall has zeroed in on Ellesmere Port when it considers throwing a thousand car workers on the dole," T&G General Secretary Tony Woodley said in a statement.
It was unclear when they planned to return to work, the union spokesman said. A source at the plant confirmed operations had stopped since the walkout.
"We are dismayed by the situation. We think that there is only one way to secure the long-term future of Ellesmere Port, and this is to improve productivity continuously and to bring competitiveness up to an optimal level," a GME spokesman said.
He said the company was not acting unilaterally but was consulting with its works councils to find the best solution possible.
Forster said Wednesday the carmaker was negotiating with labour representatives, who wanted to spread production cuts over other GM plants in Europe that make the Astra compact, but he described the idea as "not super-attractive".
"This just delays a real solution," he said on the sidelines of a ceremony opening GM Europe's design centre on Wednesday.
Forster said GM had looked to cut payrolls at Ellesmere Port, because workers there had better chances of finding new jobs.
"We know, thank God, that the English labour market is more able to absorb (workers) than that, for example, in Germany or Belgium," he told reporters.
Plants at Antwerp, Belgium and Bochum, Germany also build the Astra, which was GM's best-selling vehicle in Europe last year.
"What is at stake is giving staff whom we can no longer employ the chance to find work somewhere else. That is why our proposal was to get to grips with this in England," Forster said.
The Amicus union said the walkout was an "emotional reaction" from angry workers to comments made as the company and labour unions seek to find alternatives to job cuts.
"His comments are extremely unhelpful during critical ongoing negotiations between the company and trade unions in Germany that are not due to conclude until tomorrow," Amicus National Secretary Roger Madisson said in a statement.
Any British job losses would follow last month's decision by French carmaker PSA Peugeot Citroen to close its central England plant next year, eliminating 2,300 jobs, and the collapse of British carmaker.