The quarry extension would gobble up six public footpaths and 11 hectares of grade two farmland and provide enough stone to keep the operation going for at least another 50 years.
Ruardean parish council and the Ruardean and Drybrook Residents' Association will be vigorously fighting the proposals which are contained in the County Minerals Plan.
But local councillor Andrew Gardiner says a group of "influential" Forest councillors are saying nothing about the Drybrook plan as, he claims, they see it as the way to kill off the proposal for a new quarry at Hewelsfield.
"In my view they are quite prepared to sacrifice Drybrook and Ruardean. So far as they are concerned quarrying in the Dean is first and foremost about protecting Hewelsfield. What happens elsewhere is of little or no importance," he said.
Mr Gardiner, a district and county councillor, said discussions about the Drybrook quarry extension were being deliberately stifled.
"Though I have never advocated quarrying around Hewelsfield, I deeply resent the political demeanour of those who continue to marginalise my democratic access. They do all in their power to stop debate on the Drybrook quarry issue," he said.
The Drybrook extension is being pushed by the County Council which has to have a "landbank" of stone available to meet national targets.
"This is nothing to do with the quarry company. The County Council has apportioned quantities of stone to be extracted from the Forest of Dean and it is my opinion that because of these unrealistic quantities an unholy alliance between influential district members and the Hewelsfield lobby has come into being.
"I regret that it would appear to be at the expense of the residents of Drybrook and Ruardean and those living near Stowfield quarry.
"They hide their real intentions behind 'Special Status'. AONB and National Parks while, by implication, they would obliterate what is unrestorable heritage at Ruardean.
"At Drybrook with the current permissions plus the possibility of permission to extend westwardly, we could lose all of the historical landscape, footpaths, wildlife and natural habitat between Ruardean and Drybrook," he said.
Mr Gardiner has spent months preparing a case to put to a government inspector when the Minerals Plan is discussed in detail later this year.
Among the dozen expert witnesses who will be called to oppose the Drybrook extension will be Vicki Meek, chairman of Ruardean Parish Council.
Mr Gardiner said the approach to the quarrying issue appeared to be based on selfishness.
"I have never advocated quarrying around Hewelsfield but it would be ridiculous to agree to such a huge extension at Drybrook. It would be nothing short of a nightmare, devastating some of the finest views in the area leading to massive environmental problems from noise and dust," he said.