TWENTY-ONE of the world’s leading experts on the Stonehenge landscape have dealt a hammer blow to the government’s proposals for a tunnel at the World Heritage Site.

In a joint response to the government’s proposals, the senior archaeologists said the western entrance to the tunnel would destroy the view of the sunset at the winter solstice, the very reason the monument was built more than 4,000 years ago.

The 1.8mile tunnel would have “dreadful consequences for the world’s most famous archaeological site and its landscape setting”, said the group, which includes Mike Parker Pearson from University College London and David Jacques of Buckingham University.

They are instead supporting an option which would see the A303 diverted three miles south of the Stones, avoiding the World Heritage Site completely.

New evidence “clearly shows” the main focus of Stonehenge would have been the winter solstice sunset, rather than the summer solstice sunrise, they said, and this “remarkable astronomical dimension ... must be respected and preserved”.

The western tunnel entrance would be in line with the midwinter sunset, with headlights and street lamps blighting the view, they wrote.

“If the integrity of this south-west solstice sightline from Stonehenge is destroyed, it will forever prevent visitors to Stonehenge properly seeing the winter solstice sun setting behind the distant natural horizon – exactly as was possible in prehistoric times.”

They said the whole tunnel option was a “calamity”and the approach to a western portal would “inflict a vast gash on the landscape”.

Not only is the tunnel more expensive than the southern surface route, but it is “vastly more damaging”, and could destroy as yet undiscovered archaeology, they said.

The public consultation ends on Sunday.