No decision can be made on planning permission for a Co Tyrone gold mine until a minister is available, a Stormont department has said.
Dalradian Gold owns the Curraghinalt site near Gortin and has submitted an application for official approval.
There is no suggestion that preparatory work for the final decision, not expected for some time, has been disrupted by the impasse at Stormont.
A judge earlier this year found that the civil service had overstretched its powers in making another regionally significant decision on a waste incinerator in Co Antrim without ministerial approval.
That has had massive implications for other major decisions across the civil service.
In relation to the gold mine, an official at the Department of Infrastructure's strategic planning division wrote: "The department will not take any further decisions on regionally significant applications... while the appeal process is under way."
The letter was written before the conclusion of court proceedings in recent months, which have confirmed officials are unable to take decisions in the absence of ministers.
Northern Ireland Secretary Karen Bradley has promised to bring greater clarity around civil service powers soon.
Campaigners are opposing plans to build a gold mine at Dalradian's site.
The firm has submitted a planning application to operate the mine for 25 years, supporting 350 jobs.
The planning process is expected to take up to two years and may be the subject of a public inquiry.
Opposition has focused on environmental grounds.
It follows years of exploratory work by Canadian firm Dalradian in the Sperrin mountains near Greencastle.
Dalradian said the mine would transform the economy of the area.
Meanwhile, Declan Donnelly, part of the Ant and Dec presenting team, has tweeted his opposition to plans for unrelated mining at Slieve Gallion in Co Londonderry.
He said: "This is such a magical area where my paternal family has lived for hundreds of years and still resides.
"I have laid stones at its summit.
"It would be a travesty to destroy this wonderful mountain."