The National Trust is initiating a legal challenge to the decision to grant planning permission for a major golf resort and hotel development on green field land at Runkerry.
The conservation charity is seeking leave for a judicial review of the decision to give the go ahead for the development on land between Bushmills and the Giant's Causeway World Heritage Site.
A spokesman said: "The National Trust has consistently opposed the planning application and in particular has expressed concern that the entire development is on land which is zoned in the draft Northern Area Plan as the distinctive landscape setting of the World Heritage Site in which no development should take place.
"This is based on a recommendation by UNESCO - the body responsible for World Heritage designations - that there should be a buffer zone to protect the special landscape surrounding the Causeway.
"Having carefully considered all the information relating to the planning decision, there remain fundamental issues of concern. We therefore have no option but to seek leave for a judicial review, so that the decision could be given the fullest possible consideration."
The National Trust advocates sustainable development. The National Trust looks after and provides visitor access to the Giant's Causeway, Northern Ireland's only World Heritage Site. The Government has binding international commitments with UNESCO to protect only the World Heritage Site, its setting and wider landscape in the Causeway Coast Area of Outstanding Natural Beauty. The potential loss of World Heritage Site status is a real threat.
Background to the National Trust:
The National Trust is a conservation charity which looks after special places throughout England, Wales and Northern Ireland. We look after some of Northern Ireland's most beautiful and special places - for ever, for everyone. The places in our care range from Northern Ireland's highest mountain, Slieve Donard, to our only World Heritage Site, the Giant's Causeway; from amazing gardens like Mount Stewart and Rowallane to mansions such as Castle Coole and Florence Court and rare working mills like Patterson's Spade Mill and Wellbrook Beetling Mill.
In all, we protect and provide access to:
• Over 60 miles of coastline (about one third of NI's coastline)
• 40 square miles of countryside
• More than 200 listed buildings
• 4,000 hectares of farmed land
• Over 1,500 archaeological sites.