Campaigners have won a High Court battle over the Transport Secretary’s decision to approve a controversial road project which includes a tunnel near Stonehenge.
Save Stonehenge World Heritage Site (SSWHS) challenged Grant Shapps’ decision to back the £1.7bn scheme to overhaul eight miles of the A303, including the two-mile tunnel.
The go-ahead was given in November last year, despite advice from Planning Inspectorate officials that it would cause “permanent, irreversible harm” to the Unesco World Heritage Site in Wiltshire.
In a ruling on Friday, Mr Justice Holgate found the decision was “unlawful” on two grounds.
He concluded that there was a “material error of law” in the decision-making process because there was no evidence of the impact on each individual asset at the historic site.
He also found that Mr Shapps failed to consider alternative schemes, in accordance with the World Heritage Convention and common law.
The judge said: “The relevant circumstances of the present case are wholly exceptional.
“In this case the relative merits of the alternative tunnel options compared to the western cutting and portals were an obviously material consideration which the (Transport Secretary) was required to assess.
“It was irrational not to do so. This was not merely a relevant consideration which the (Transport Secretary) could choose whether or not to take into account.
“I reach this conclusion for a number of reasons, the cumulative effect of which I judge to be overwhelming.”
John Adams, SSWHS director and acting chairman of the Stonehenge Alliance, said: “We could not be more pleased about the outcome of the legal challenge.
“The Stonehenge Alliance has campaigned from the start for a longer tunnel if a tunnel should be considered necessary.
“Ideally, such a tunnel would begin and end outside the WHS. But now that we are facing a climate emergency, it is all the more important that this ruling should be a wake-up call for the Government.
“It should look again at its roads programme and take action to reduce road traffic and eliminate any need to build new and wider roads that threaten the environment as well as our cultural heritage.”
The Stonehenge site, together with Avebury, was declared by Unesco to be a World Heritage Site of Outstanding Universal Value in 1986 on account of the size of the megaliths, the sophistication of their concentric plans and the complexes of Neolithic and Bronze Age sites and monuments.
The proposed tunnel is part of a £1.7bn investment in the A303 between Amesbury and Berwick Down.
The road, which is a popular route for motorists travelling to and from the South West, is often severely congested on the single carriageway stretch near the stones.
Highways England says its plan for a two-mile tunnel will remove the sight and sound of traffic passing the site and cut journey times, but some environmentalists and archaeologists have voiced their opposition to the plan due to its potential impact on the area.
The project is classified as nationally significant, which means a development consent order is needed for it to go ahead.