Workers were being told the bad news on Thursday morning
A paving stone plant which employs 55 workers in Wrexham is to close after talks over a rescue package failed.
About a third of the workforce at Marshalls in Llay will be laid off on Friday, with the rest to follow once a shutdown date is set.
Peter Hughes, of the Unite union, said he was "bitterly disappointed" and had been meeting workers at the factory on Thursday morning.
A company spokeswoman said it was "very sad" but closure seemed inevitable.
Marshalls announced the closure, and proposals to scale down other plants, in reaction to what it called "uncertain" markets earlier this month.
In response, workers at the plant agreed to stay at home for two weeks or more without pay in an effort to improve the balance books.
The union had also planned to ballot its members across the UK to see if they would forego a pre-agreed pay rise which would have raised enough money to keep the Llay plant open for 12 months.
However, the ballot was abandoned because the company refused to guarantee that other plants would not close in the future.
The union also wanted the company to agree that the pay rise could be awarded if the company became profitable enough at a later date.
Mr Hughes, senior regional officer with Unite, said the union had exhausted every avenue to keep the plant open.
A Marshalls spokeswoman said: "It's very sad, but we will continue to give our employees every support."
Marshalls currently employs about 3,000 workers and is holding consultations on the closure of its Hambrook site in West Sussex, where 25 jobs are set to go.
About 55 jobs are also set to be cut at its display centres around the UK.