Hundreds of staff at the Airbus UK factory in north Wales have walked out in unofficial strike action over proposed job cuts.
The wings for the Airbus A380 are made at Broughton
It is thought many of the 7,000 workers in Broughton, Flintshire, which makes wings for Airbus' flagship A380 passenger jet, are involved.
Unions at the plant said they were not supporting the action and have urged their members to return to work.
Airbus confirmed "several hundred" workers had taken unofficial action.
Rob Dowey, convenor for the union Amicus at Airbus, said he was trying to persuade staff at Broughton to return to work.
He said: "There has been an official walkout at Airbus. I've asked people to remain at work but they decided the situation is such that they wanted to take unofficial action.
"It's started with this morning's shift and has gone on to this afternoon.
Around 900 workers held a protest in Chester last week
"Primarily they are concerned about the future and people being out-sourced."
Airbus revealed in February it was planning to cut 10,000 of its 57,000 jobs over the next four years.
Its plans would see 4,300 jobs go in France and 3,700 in Germany.
Up to 1,600 jobs are expected to be lost at Broughton and Filton, near Bristol, in the UK and 400 in Spain.
Delays in the company's flagship project to build the A380 superjumbo are set to cost the firm at least 4.8bn euros.
Earlier this month, thousands of Airbus workers in France and Germany went on strike over the planned job cuts.
About 900 workers at Broughton held a rally in Chester last week over the expected cuts at their site.
Responding to the walkout, Airbus confirmed "several hundred" workers had taken unofficial action.
A spokeswoman said: "Both production shifts took part in unofficial action.
"We understand it was caused by disappointment over the news that there would be no profit-share payment this year."
She added that staff were expected to return to work as normal on Monday.