Farmers in Askeaton, Co Limerick, have criticised plans by the Taoiseach to visit the Aughinish Alumina refinery on Friday.
Mr Ahern will call to the facility on the Shannon Estuary to view progress on the construction of its combined heat and power plant. Most of the electrical energy produced will be fed into the National Grid.
However, the Cappagh Farmers Support Group said it was "a disgrace" that the Taoiseach would make a special effort to visit the plant when neither he nor his ministers had ever visited them to hear about their concerns over animal deaths and human ill-health.
Mr Pat Geoghegan, spokesman for the group, said three successive ministers for the environment had ignored invitations to come to Limerick and hear the farmers' concerns.
The farmers' group has been calling for an inquiry into the State's handling of unexplained animal deaths in the Askeaton area. The group estimates that some 1,500 animals have died mysteriously in the past decade.
A €5 million inquiry by the Environmental Protection Agency failed to pinpoint the cause of the deaths. The report found no link between local industry and the ill-health of animals, and said the most likely causes related to infection, nutrition and farm management.
More recently, the farmers' group has been seeking an investigation into a tailings pond at the Aughinish Alumina plant.
The pond is made up of red mud, the main by-product after alumina is extracted from bauxite ore. The farmers' group said it had concerns about the health effects of the pond on their families and animals.
Aughinish Alumina has refused to comment on the allegations on the basis that this would lend credence to them.
However, when it emerged that the Joint Oireachtas Committee of the Environment had listed the issue on its agenda, the company's managing director, Mr Damien Clancy, wrote to it, asking that it not discuss the matter.
In the letter, Mr Clancy said the company was concerned "that the hearings of your committee will be used to allow the repetition of defamatory and unsustainable allegations".
He said the people making the allegations would "undoubtedly be assisted by a sensationalist press" and he insisted that the company was "one of the most highly regulated, supervised and independently investigated industries in the State".
The committee decided to refer the matter to the Oireachtas Joint Committee on Health.
