The Tánaiste Ms Harney said today a decision by Bord Gais to end a credit arrangement with Irish Fertilizer Industries (IFI) was partly to blame for yesterday's decision to close the company.
IFI informed its staff yesterday that the company was to close its plants in Cork, Arklow and Belfast with the loss of 620 jobs.
Ms Harney said that Bord Gais had decided to discontinue its 60-day credit terms to IFI and this would have cost the fertiliser company over €8 over the next two months.
IFI's contract with Bord Gais to buy two thirds of its gas ended last month.
Bord Gais is understood to have stipulated payment in advance as part of any future contract. This was to avoid exposure to liabilities.
Labour deputy for Cork, Ms Kathleen Lynch, described Ms Harney's comments as "a pathetic attempt to divert from her decision from decision to pull the plug the plug on more than 600 jobs."
"It may well be that the decision of Bord Gais to change its credit terms made the situation more difficult for IFI. However, Bord Gais is owned by the State and Minister Harney, as a major shareholder in IFI, should surely have raised this matter with the relevant Minister."
Speaking in the Dáil today, the Taoiseach, Mr Ahern, desrcibed IFI's closure as a tragedy for the workers but it was not possible to save the company from mounting losses.
Last night, Ms Harney said that considerable efforts by the company to devise a business plan had not succeeded.
The State and ICI, joint owners of IFI, would now co-operate with the liquidator "to ensure that the process can be as smooth and as efficient as possible".