Scottish Borders Council has decided to object to plans for a 36-turbine wind farm near the scenic Devil's Beef Tub.
The neighbouring Dumfries and Galloway authority has already voiced its "grave concerns" about the plan.
SBC has now formally opposed Wind Energy Ltd's Earlshaugh project on the grounds of its landscape impact and adverse effect on habitat in the area.
The objection means that the proposal will have to go to public inquiry before a decision can be made.
The wind farm site is located in the Scottish Borders but lies within a few miles of neighbouring Dumfries and Galloway.
Because of the scale of the development, the planning application is being considered by the Scottish Government.
However, SBC is a statutory consultee and its objection means an inquiry must be held.
Councillor Carolyn Riddell-Carre said: "One of Scotland's greatest assets is its landscapes and this is a designated area of Great Landscape Value and must be protected.
"We should indeed object to this proposal."
Concerns were also voiced about the cumulative effect of the turbines along with other developments in the area.
The Devil's Beef Tub acquired its name from its historical use as a site to hide stolen cattle.