The Save Red Rock and Shielmartin Hill campaign, aimed at preserving traditional walking routes and rights of way on Howth Head, will today challenge a local landowner's claim that he should be allowed to fence off his property.
Mr Gerry Gannon, who owns several holdings on Howth Head, last year paid £200,000 for an 11acre site at Middle Mountain, and erected a wooden fence around it.
According to Mr Gannon, the fence is necessary to keep livestock on the land. Specifically, he says he wants to keep two horses and a donkey on the land for use by his daughters.
However, he insists that vandalism of the wooden fence has meant that he "was wandering all around Howth at two o'clock in the morning looking for livestock".
When the fence became damaged, Mr Gannon applied to Fingal County Council for planning permission to replace part of it with a wall and metal fence. This was refused by the council and Mr Gannon has appealed to Bord Pleanala.
Speaking to The Irish Times, Mr Gannon, who is a property developer, insisted that there was "no hidden agenda" to build on the land.
While he acknowledged that there was a dispute with local people over the fence, he insisted that "there is not now, nor was there ever", a right of way across the land.
"Before I signed the contracts for this land, I wrote to the local landowners and interested bodies, asking them if they felt there were any such rights. No one replied even though I wrote two or three times.
"What they are claiming now is nonsense. I have a permission for a stable across the road and I want to keep the livestock between it and the fenced land."
However, members of the Save Red Rock and Shielmartin Hill group will today lodge 15 separate affidavits with Bord Pleanala, part of a combined "observation" which insists that there are traditional walking rights across the land.
A spokesman for the group, Mr Michael McCarthy, who lives locally, says the land is part of an area which was the subject of a protest march by 800 people aimed at maintaining the rights of walkers on the Head.
He said the perception was that Howth Head would soon be granted a Special Area Amenity Order (SAAO) and people felt that the protection of their walking routes was organised.
"The fact is that this wall is attempting to close off traditional rights of way which have been enjoyed by people, not just local people, for years.
"This, taken with the raising of heights on walls along the roadside, has severely curtained the views and amenities of the area and must be opposed."