Trade union chiefs are trying to track down those behind an Irish consortium which bought the Clerys department store and pulled down the shutters.
A rally in support of hundreds of staff will be held over lunchtime tomorrow after they were dramatically told on Friday the historic property on Dublin's O'Connell Street was being closed.
Meetings are taking place tomorrow between Siptu representatives and accountants overseeing the liquidation but efforts to trace the investors behind the Natrium consortium have been unsuccessful.
One member of staff, John Finn would have had 43 years service in the store in September and was given 20 minutes to leave the building when the investors took over.
"If they had any decency and respect for people who have worked all their lives, and even for the young people in the store, they would have come to speak to us face to face, that was disgraceful," he said.
"There's a lot I'd like to say to them, but it's not printable."
Mr Finn was a Siptu shop steward in Clerys and put a call out on the store's tannoy to notify staff and shoppers it was closing.
Siptu have been attempting to make contact with those behind the buyout, including calling at offices in Dublin city centre, but to no avail.
Sector organiser Teresa Hannick said: "The way these workers have been treated by Natrium, the consortium which took over Clerys on Friday and then liquidated the company, is completely unacceptable.
"What we are looking for is Natrium to do the right thing and treat these people with a bit of respect."
There is speculation the Natrium consortium bought the store to redevelop on the site.
Some 130 people were employed directly by a company set up to run Clerys when it was bought by US investors Gordon Brothers Europe in 2012 from the Guiney family.
Another 330 are employed by the 50 concession holders who operate in the department store.
Tanaiste Joan Burton said social welfare officials will brief all staff and their union representatives on their rights and possible state benefits over the next week.
"This is a very difficult time for the staff of Clerys who gave so much to the company and, frankly, have been treated very badly," she said.
There is no prospect of jobs being saved at this stage and trade union chiefs are holding talks with KPMG to find out whether workers will be classed as preferential creditors when redundancy is being calculated.
At present staff will only be eligible to two weeks pay for every year of service.
"These workers have hundreds of years of service between them and should be treated with the due respect they deserve," Ms Hannick said.
Siptu will meet KPMG in Liberty Hall tomorrow before a delegation of workers and union officials meet with junior minister Ged Nash to seek assurances that workers' concerns about how they have been treated by the new owners of the company will be addressed.
Trade union organiser Robert Purfield said: "The treatment of these honest hard working people marks a new low in the annals of Irish business practice.
"Unfortunately, it would seem to be part of a pattern of behaviour by some businesses of showing a complete disregard for loyal workforces, as was the case last year in Dublin with the Greyhound Recycling dispute and in 2012 with the Vita Cortex dispute in Cork.
"It is a situation which will not be allowed to continue."
Jobs Minister Richard Bruton said it was a "particularly appalling" way for workers to lose their jobs.
Clerys survived wars and storm damage although it did claim £78,556, one shilling and eight pence, after the building was destroyed during the 1916 Easter Rising.
The store was one of the first of its kind in the world and has been in business for 162 years.