Workers received the letters on Saturday morning
Nearly 300 workers at a printers in Somerset have been told they have been made "redundant with immediate effect".
All 287 workers at Butler and Tanner Printers Ltd in Frome received a letter on Saturday telling them the company is being liquidated.
The news came as negotiations between the Unite union and Butler and Tanner were taking place at conciliation service ACAS in Bristol.
Unite said an average salary of £1,200 was due to each employee this month.
The letters received by staff stated that the company was "unable to invoice sufficient work to pay this month's wages" and that "strict security" had been imposed at the site.
Parent company Media & Print Investments Plc (MPI) said the union's failure to resolve working practices meant finances had been withdrawn.
Chairman, Mike Dolan, said: "Shareholders were unwilling to pour good money down what they consider to be a drain and they declined to make further funding available.
"Their [the union's] miscalculation has cost 300 people their jobs and sadly, 100 of those people were not even in the union
"The union has shown utter contempt for its own members and Butler & Tanner by unnecessarily publicising their strike threat in a crass attempt to exert pressure on the company.
"That was an act of wilful economic vandalism which frightened off too many of our customers, suppliers and financiers."
Mr Dolan said if the threat of industrial action had been lifted MPI would have funded the business through what is traditionally a quiet time for Butler and Tanner.
National officer for Unite Ann Field said: "Unite will be demanding recompense in full from the perpetrators of this despicable act sacrificing people's jobs and livelihoods.
"Mike Dolan and former boss Andrew Hillman should be called to account for what they have done to the workers' jobs, their pensions and their community."
The management was still at the debating table on Friday and gave no indication the company was about to be closed, Ms Field said.
Butler and Tanner produces hardback colour books including those of Jamie Oliver, Delia Smith and Nigella Lawson.
The closure will not have any impact on the other trading companies of MPI including BAS Printers, Borcombe SP, Goodman Baylis and Friary Press