Campaigners fear the "peace and tranquility" of Dartmoor could be destroyed if the Ministry of Defence is granted permanent permission for training exercises.
Members of Dartmoor National Park Authority will decide tomorrow on the MoD's application to continue to use Cramber Tor, on the south west of the moor.
But it has attracted widespread opposition from environment groups who fear that up to 700 personnel could be involved in mock battles on the sensitive site.
James Paxman, chief executive of the Dartmoor Preservation Association, said it was "deeply concerned at the possibility of battle simulation" which would "destroy the peace of this tranquil area".
He has called for new conditions to be imposed to limit the number of troops and aircraft and said permanent permission would leave the authority with no control over military activity.
A report to authority members said new conditions "are, in a number of areas, tighter than those imposed previously".
"The applicants have stated it is not their intention to intensify the use of land and that they are merely seeking a permission to do what they've done for the last 30 years," it says. Any significant increase in intensity of the use or the way in which the land is used will take the use outside the conditions and require a fresh planning permission."