The president of the Irish Farmers Association, Mr John Dillon, has threatened that its members will refuse to remove their sheep from mountain commonage to prevent overgrazing.
More than 1,500 hill farmers along the western seaboard attended a public meeting on destocking organised by Mayo IFA in Castlebar on Monday night.
Many of them have been told they must dramatically reduce the number of sheep they keep on commonage to conform with a new programme to prevent erosion, which many believe will drive them out of business.
Department of Agriculture and Dúchas representatives explained to the meeting the value of the Rural Environment Protection Scheme and why sheep destocking was essential. They were also informed how the commonage framework plan would address the problem of overgrazing on the hills.
However, for the most part, the sheep farmers affected by the commonage framework plans refused to accept the department's stance. They argued instead that because of it, they were being driven off their land and out of sheep-farming and the compensation offered was not enough.
Mr Francis O'Malley, chairman of Mayo Hill Sheep Farmers, accused the department and the minister of missing the point on farmers' concerns.
"We're sick and tired listening to Joe Walsh and Éamon Ó Cuív telling us they have our interests at heart. The main issue, which they consistently fail to address, is that we want the decoupling of green land from the commonage."
Most farmers had expected they would only have to destock their upland mountain land and that no action was to be taken on lowlands, so-called greenlands, where they normally keep their sheep in the winter.
"We had been told it was a commonage framework plan and there was never a mention of action to be taken on our green or lowland yet that is exactly what's happening and that's the crux of farmers' frustration," Mr O'Malley said.
The farmers said the plan could seriously devalue many farms in Mayo. "The plans themselves may have merit," former IFA sheep committee chairman, Mr Michael Holmes, argued, "but the problem is the formula used and then implemented on green land and lowland, resulting in the devaluation of our farms."
Mr Dillon called on Mr Walsh to change immediately the destocking calculation. He said the IFA wanted an answer within a week, otherwise farmers would refuse to destock sheep.