There is a risk of a "catastrophic failure" for the Great Stalactite in Pól an Ionáin cave in north Co Clare if it is developed as a tourist attraction.
That was the warning issued yesterday by the Pól an Ionáin Action Group as it sought to overturn a decision by Clare County Council granting Mr John Browne and Ms Helen Browne, of Ardeamish, Lisdoonvarna, permission to develop the cave.
The cave contains the Great Stalactite, which, at 23ft, is reputedly the largest free-hanging stalactite in the world.
However, the action group, which has opposed plans to develop the cave for over a decade, believes the stalactite could face a catastrophic failure a during excavation in developing the plan.
It failed to prevent the development getting the go-ahead in the early 1990s. However, the plan did not proceed as the Brownes allowed the permission to lapse after five years due to a High Court dispute with a local landowner.
In 2001, the action group was successful in opposing the development when the Brownes were unable to complete an Environmental Impact Statement for An Bord Pleanála.
Now the Brownes have secured council permission for a scaled-down proposal, which omits the original interpretative centre, restaurant and 70 space car-park.
However, appealing the council decision, the action group claims that "if the works are permitted, then there will be irreversible changes made to the cave system".
The plan has the support of many businesses in the area, which have signed a petition saying this was the kind of sustainable tourism that would benefit Doolin. In granting planning, the council's planner said it would serve as an alternative tourism package to the public.
An Taisce has appealed the council's decision, and a ruling by the planning board is expected this year.