The campaign group, calling itself Save Stonehenge World Heritage Site, wants the court to rule that Planning Inspectorate advice is binding on ministers, not advisory.
The Planning Inspectorate recommended that consent for the £1.7bn scheme be withheld but transport secretary granted the necessary development consent order anyway.
Save Stonehenge World Heritage Site has instructed counsel and law firm Leigh Day to investigate the lawfulness of the secretary of state’s decision. A letter has been sent to the Department for Transport outlining its concerns.
The A303 Amesbury to Berwick Down (Stonehenge) scheme comprises eight miles of dual carriageway, a two-mile tunnel and two new junctions. It also includes a new bypass to the north of the village of Winterbourne Stoke.
The project is designed to ease congestion in the vicinity of the Stonehenge world heritage site, a notorious bottleneck on the A303 for traffic between the southeast and the southwest of England.
The Stonehenge Alliance is supported by: Ancient Sacred Landscape Network; Campaign to Protect Rural England; Friends of the Earth; Rescue; the British Archaeological Trust; and Transport Action Network.