Around 350 Irish Fertiliser Industries workers have mounted a demonstration outside the Tanaiste's office in Dublin to protest at their treatment since the Government put the company into liquidation.
More than 600 workers from Cork, Arklow and Belfast are set to lose their jobs following the closure of the company's plants.
The workers said Tanaiste Mary Harney promised on October 17 the Government would put money aside for redundancy payments and would issue advice on taxation, pension rights and social welfare entitlements.
However, none of those pledges had been honoured, they said.
Workers’ spokesman Stephen O’Riordan said: “Our man gripe is that two thirds of the employees are being taken off the payroll without their statutory entitlements.
“It is totally unacceptable that they are being thrown on the scrapheap without dignity after many years of service.”
The protest was backed by Sinn Fein Dáil member Aengus O Snodaigh.
He said: “There is a clear inequality in how workers are being treated.
“The Government must set a positive standard in dealing with redundancies – there is an onus on them to be fair to all these workers, from Arklow, Cork and Belfast.
“All of them must be given a fair deal – and the Belfast workers must get a deal equal to that of their counterparts in this state.”
A spokesman for Ms Harney said the Government was committed to providing a fair redundancy package.