After two reversals in the Court Of Session, campaigners are challenging the Cairngorms National Park Authority's planning blueprint, which would allow large scale housing developments.
These include a new eco-friendly village near Aviemore, at An Camas Mòr, with up to 1500 houses over the next 20 years; 117 homes in the village of Carrbridge, 300 at Kingussie and 40 at Nethy Bridge.
On Friday the park authority will reconsider the permission it gave in principle in 2010 for An Camas Mòr.
This is in the light of new environmental and other information emerging from the legal challenges and elsewhere and "a number of material changes in the policy context." But planning officials are recommending continued support.
The Invertebrate Conservation Trust, the Badenoch & Strathspey Conservation Group, the Cairngorms Campaign and the Scottish Campaign for National Parks had argued the developments were a threat to wildlife and ecology protected by the European Habitats Directive.
They had insisted an appropriate environmental assessment of these developments should have been undertaken prior to them being included in the park authority's local plan and not postponed to a later stage in the planning process.
Last month judge Lady Paton rejected these arguments and found the park authority had acted reasonably.