A major, ambitious and controversial tunnel boring project has faced another delay, despite the conveyor belt installations, boring mechanisms and plans all being in place, due to the result of a legal challenge.

The A303 Amesbury to Berwick Down tunnel, often known simply as the Stonehenge road tunnel, has been planned in one form or another since 1995, as a way to ease congestion around the World Heritage Site, but has been controversial for this very reason.

The most recent news is that a legal challenge that was dismissed in February 2024 will be heard in the Court of Appeal, delaying the project for at least as long as the legal challenge continues.

The issue, as it was in 1995, was that the proposed plans to bore a tunnel underneath part of the site led to concerns that it would lead to permanent destruction of architectural history, particularly since the proposed plans were for a cut-and-cover tunnel rather than a bored one.

The first attempt, with plans published in 1999, was abandoned in 2005 due to increasing construction costs, and it would take until 2017 for a variation of the project to gain approval, aided by the support of the concept by organisations such as the National Trust, Historic England and English Heritage.

However, it was condemned by UNESCO, Friends of the Earth and The Campaign for Better Transport, who alongside the Stonehenge Alliance would start to protest and criticise the plans.

This eventually led to a 2021 legal challenge which deemed the decision to go ahead with its construction as “unlawful”.

It was approved a second time in 2023, but a second legal challenge was dismissed in February 2024, with the presiding judge claiming that the plaintiff, Save Stonehenge World Heritage Site, had a case that was “unarguable”.

However, with this decision open to appeal, the tunnel project may once again be delayed or significantly altered just at the moment when work was about to begin on it.