BASC, Countryside Alliance, the Game Farmers' Association and the National Gamekeepers' Organisation have been granted permission by the High Court to each register as a joint interested party in the Wild Justice proceedings against Defra.
Permission was granted despite Wild Justice opposing the applications.
Interested party status allows the organisations to take part in the proceedings, view papers and provide evidence to counter the challenge where necessary.
This case will see Wild Justice claim that releasing birds, even at considerable distance, could damage Special Protections Areas (SPAs), Special Areas of Conservation (SACs) and Ramsar Sites. They will argue that no gamebird releasing should be allowed unless an assessment has shown there will be no impact on such sites.
A spokesperson for the organisations said: "The decision to allow us to become interested parties shows the court's recognition of the contributions that we can make to the issues being decided and its understanding that any eventual decision could significantly impact our members.
"The importance of becoming an interested party cannot be overstated. However, the work has only just begun."
They added "Judicial reviews can take time, so we advise all members who could be impacted by this challenge to remain up to date with the latest information and feed into the organisations whenever possible."