The proposed highway tunnel near Stonehenge that loomed over a recent UNESCO ruling has been called off thanks to a court order preservationists across the UK are referring to as a “wake up call” for Conservative politicians behind the controversial £1.7 billion ($2.4 billion) development project.

Activists are celebrating after a legal challenge against an approval granted last year by British Transport Secretary Grant Shapps was upheld by a High Court judge in London on Friday. The ruling cited the government’s own guidelines regarding the consideration of alternative schemes in a process that deliberately excluded impact assessments, something Justice David Holgate deemed irrational.

A plan that would revitalize an eight-mile-long section of the A303 road was first brought forth in 2017 and called for the installation of a tunnel near the 5,000-year-old ruins that opponents claim would significantly harm Stonehenge’s integrity and authenticity as a cultural site. Highways England claims the improvement project would clear a jam in the highway that has been the subject of numerous expensive overhaul proposals dating to the Thatcher administration. 

The area is rich in archaeological sites like Blick Mead, and the threat caused by the highway construct was significant enough to prompt a warning from UNESCO ahead of its annual meeting which took place July 19th. The body then formally added Stonehenge to its list of Heritage Sites in Danger and has promised to remove it altogether should an unamended form of the project somehow still go through.

Incredible news. Hugs all round. https://t.co/iUpgWu6k1K
— Stonehenge Alliance (@SaveStonehenge) July 30, 2021

Both the National Trust and English Heritage, the group which operates Stonehenge, are in favor of the new project, claiming the new tunnel would unite the site’s two-sided program and reduce traffic noise in its vicinity. The government now has the option to appeal the court’s decision. A transport official told The Guardian that the office is “carefully considering the judgment and deciding how to proceed.”

Construction was expected to begin as early as this month before the court’s ruling. The Financial Times has more on the High Court’s rulings here.