A group of residents who lost their High Court battle over a proposed gold mine in Co Tyrone are to take their case to the Court of Appeal.
Greencastle Rouskey Gortin Concerned Community (GRG) mounted a judicial review challenge to the Department for Infrastructure's decision to consider a planning application from Canadian firm Dalradian.
They claimed insufficient information was provided before the 10,000-page planning application was submitted, arguing that the preliminary consultation exercise was significantly flawed.
But in February Mr Justice McCloskey held that planning laws did not require the developer to publish and consult on a finalised scheme at that stage.
Dalradian has claimed that its 25-year project could support 350 jobs in the area, offering a significant boost to the economy.
Announcing the plan to appeal February's decision, solicitor for the residents, Andrew Ryan from law firm TLT, said: "GRG's carefully considered decision to appeal the decision of the High Court demonstrates the clear determination that the group has to ensure that no stone is left unturned in challenging the actions of the Department for Infrastructure and its consideration of the planning application to date.
"This is an entirely new and previously unchallenged area of law and the group firmly believe that the issues raised in the High Court warrant further examination by the Court of Appeal."
Rachel Taylor from planning consultancy Clyde Shanks, who is representing the GRG group, added: "While the judgment acknowledged that the challenge was well brought and raised important and interesting questions, in my view questions still remain regarding the plain fundamental differences between the pre-application notification which informed the community consultation exercise and what was eventually submitted in the subsequent planning application."
Martin Conway from GRG said the residents believe there are still substantive issues of law and fact that have not been addressed. "The High Court recognised that this challenge might ultimately prove to be the first major staging post in a lengthy legal struggle and that the real battle has just begun in earnest. This is indeed the case and we are determined to fight the application every step of the way."
Dalradian said after February's ruling that it is looking forward to its planning application proceeding through to the public inquiry stage.
"We will continue to work constructively with the local community and to further develop our relationships with our near neighbours," the company said.
"Modern mining is a new sector for Northern Ireland and can provide sustainable employment for decades to come."