Under the new plans, the controversial 3km tunnel is to be extended slightly to avoid precious archaeological sites, while the twin western portals have been redesigned with a grass covered canopy to improve the landscape. A viaduct is also planned to carry four lanes of motorway standard ‘expressway’ over the River Till.

 

Highways England says its plans for the £1.6Bn project – which are being consulted on until 6 April – will restore the ‘tranquil environment and setting’ of the Stonehenge monument and its surroundings.

 

The company has worked with various heritage groups and archaeology experts in a bid to minimise disruption and damage to the world heritage site. But some campaigners remain unsatisfied at the revised plans.

 

“However well designed, the devastating impact of this road engineering would destroy archaeology and deeply scar this iconic landscape and its setting for ever,” read a statement from the Stonehenge alliance, which includes Friends of the Earth, the Campaign for Better Transport and RESCUE – The British Archaeological Trust.

 

A leading archaeologist from the University of Buckingham, Professor David Jaques, has also warned that a drop in the water table caused by the project will destroy a key Ice Age site at nearby Blick Mead. He said: “The Stonehenge world heritage site landscape is unutterably precious and you tamper with it at your peril – you cannot make it come back.”

 

Others, however, take a more positive stance. A joint statement from Historic England, the National Trust and English Heritage welcomed the revised plans, which they said have the potential to “protect and enhance” the world heritage site. They added that a tunnel with the right design would “reunite a landscape that has been severed by the A303 for generations”.

 

“We will continue to engage with international heritage advisors and others to help to ensure Highways England fully assesses the heritage impact and comes up with the right solution,” the statement said.

 

Responses to the current consultation will help shape the scheme further before Highways England submits an application for a development consent order. Work on the A303 Stonehenge tunnel scheme could begin by 2021 and complete by 2025.