Bleaklow Industries and its contractor Merrimans have permission to remove fluorspar from Backdale Quarry near Hassop. But the Campaign to Protect Rural England (CPRE) and local group Save Longstone Edge claim that the operators are removing limestone only, which they say is not covered by the permission.
The quarry, which forms part of Longstone Edge, was reopened four months ago for extracting fluorspar. This followed the cessation of quarrying activity in 1998, when attempts by the Peak District National Park Authority to control the site ended in the High Court.
The CPRE pointed out that normal practice when digging for fluorspar is to use waste limestone to restore the land to its original state.
It has written to the two companies to demand a halt to any further limestone extraction to avoid land damage.
But Robin Harpley of Bleaklow Industries insisted that the planning permission for Longstone Edge authorises extracting three named minerals plus "any other minerals that are won in the course of winning the materials".
He added: "Limestone, the host rock, has been won and sold from sites on the permission continuously since 1988. At no time has enforcement action been taken by the planning authority."
The park authority confirmed that the site is covered by a 1952 consent for extraction of vein minerals. But its head of development control, John Davies, added: "We do not accept that this consent allows for the extraction of limestone and we are seeking legal advice."