Workers at Irish Fertilizer Industries (IFI) were told by the Tánaiste, Ms Harney, yesterday that there was no prospect of an increase in their severance package.

The news was greeted with "outrage", and sit-ins at the company's plants in Arklow and Cork are considered likely.

About 100 staff at the company's Belfast plant are already staging a sit-in, having begun the action last Tuesday to highlight a shortfall in their pension fund and their demand for improved severance terms.

IFI, jointly owned by the State and British chemical giant ICI, was placed into liquidation with the loss of 620 jobs in October.

The two shareholders have jointly funded a €24.5 million severance package, worth an average of €50,000 to each worker, in addition to statutory redundancy terms.

Workers say this amounts to between two and two-and-a-half weeks per year of service, well short of the five-and-a-half weeks they would have expected.

At a two-hour meeting with union leaders yesterday, which was also attended by representatives of ICI, Ms Harney said there would be no increase in the terms on offer.

A spokesman for the Tánaiste said she had told the meeting there would be a further payment if there was a surplus remaining at the end of the liquidation process.

Mr Noel Dowling, national industrial secretary with SIPTU, said the liquidation process could take three to four years.

Union members were "outraged" by the outcome of the meeting, he said, and had returned to their home areas to consider their next move.

Union leaders were told at the meeting that an orderly wind-down of the company would facilitate the generation of a surplus after liquidation. Workers have made it clear, however, that they are not in the mood for co-operation, and action to prevent such a wind-down is considered likely.