Plans by Roadstone for a major quarry in Co Mayo are being opposed by a number of local residents for environmental and traffic reasons.
The five objectors claim the 39 hectare quarry at Islandeady, Castlebar, would cause increased levels of dust and noise in the area and increased traffic.
They also claim that wildlife would be adversely affected and that property values would go down.
According to the objectors, there would be a visual impact due to the proposed bridge across the adjacent Dublin to Westport rail link.
Roadstone Provinces Limited of Saggart, Co Dublin, wants to develop a quarry which would employ in the region of 30 people to replace its old facility at Moneen, Castlebar, where the limestone supply is running out.
The company was recently granted full planning permission by Mayo County Council for the proposed new quarry, but this was overturned on appeal to An Bord Pleanála, which believed the proposal was premature pending the development of a new N5 road linking Westport and Castlebar.
In its second application for planning permission, Roadstone has warned that the delay in completing the N5 is "jeopardising the company's future involvement in the Co Mayo area".