The Irish Farmers' Association has pulled out of the Government talks on social partnership.
IFA President Padraig Walshe has accused the Departments of Agriculture and Environment of undermining the negotiations for farmers' involvement in a new national partnership by announcing the imposition of the Nitrates Directive while the first partnership meeting was actually in progress.
'It was bad faith and completely at variance with the positive statements inside the talks and I have suspended IFA's involvement in partnership,' Mr Walshe said.
He added that he would not lead farmers into what he described as a charade.
Farmers say the directive, which puts curbs on the amount and timing of the spreading of farm manure, is unworkable.
It comes as an Oireachtas Committee met to discuss the directive which was signed into law by the Minister for the Environment, Dick Roche, last December.
Its aim is to try and reduce the high level of pollution caused to ground water by agricultural fertilisers.
An official from the Department of the Environment told the Joint Committee on Environment and Local Government that phosphorus had been identified as the biggest source of water pollution in Ireland.
John Sadlier also said he believed the threat of a heavy fine from Europe had now receded since the Nitrates Directive was implemented.
Dr Seamus Cross of Teagasc told the committee that the agency had said on many occasions that the current legislation would provide difficulties for the Irish pig industry.
Michael O'Donovan from the Department of Agriculture and Food said it would be taking out an advert in the Irish Farmers Journal regarding the new regulation, and is also preparing a handbook for farmers on the matter.
