Photo: a graphic mock-up shows the proposed route of the 2.1km bored tunnel.

Instantly recognisible and for many the most clear and potent link we have with our prehistoric past, Stonehenge is among the world's best-known heritage sites.

It is hardly surprising that it stirs passions in a manner unlike any other ancient British monument.

As the deadline for raising objections to the Government's road development plans for the Stonehenge World Heritage Site approaches, experts have been airing their opinions on the controversial scheme.

Speaking to the 24 Hour Museum, Chris Woodford of Save Stonehenge explained how his organisation has been doing all it can to encourage objections to the Government's plan before the September 4 deadline.

"What they will be doing is improving part of the landscape in the immediate vicinity of the stones themselves, but at the expense of the wider heritage site," said Chris.

Photo: currently two roads, the A344 and A303, run through the World Heritage Site and are used by a constant stream of traffic. © English Heritage.

What Chris, and many other dissenting voices are anxious about, is the surrounding environment of an area littered with prehistoric sites. Campaign groups are calling for a full exploration of alternatives, including bypassing the World Heritage Site entirely.

As reported on the 24 Hour Museum, in December last year the Department of Transport unveiled plans to close the A344, which runs directly alongside the ancient stones, and turn the neighbouring A303 into a dual carriageway.

Alongside a proposal for a new visitor centre, the £183 million scheme involves boring a 2.1km tunnel under the site to house the section of road that runs closest to Stonehenge itself.

While experts appear to agree that a bored tunnel is preferable to the original 'cut and cover' design, many are vehemently urging the Highways Agency to consider alternatives.

George Lambrick, Director of the Council for British Archaeology, told the 24 Hour Museum that his organisation would be launching an official objection in the next few days.

Photo: the motives for building Stonehenge 2-3000 years ago have been the subject of constant speculation. © English Heritage.

"We welcome that there is a bored tunnel slightly longer than the original one, but we are concerned about the damage on either side of it and we don't think that it's fully achieving the improvements the site deserves," he said.

Adding that the plans were not in line with the World Heritage Site management scheme, which requires the entire site to be free of roads, Mr Lambrick was adamant that longer tunnel options already explored and rejected due to cost, should be looked into further.

"It is about investment in long term benefits for future generations rather than the immediate future."

This position is also supported by the National Trust that owns and looks after the land surrounding Stonehenge. The Trust has launched an objection of its own, unconvinced that a 2.1km tunnel will adequately safeguard the integrity of the site.

Dr Francis Pryor MBE, President of the CBA and renowned expert on prehistoric Britain, counselled a more balanced approach to the plans.

Photo: an artist's impression shows how the Government is intending to turn the existing A344 into a bridleway.

"My personal view is best summed up by the thought that we've got to do something," explained Dr Pryor.

"The worst outcome would be for the archaeological world to disagree so strongly that the current scheme came to nothing and that we were left with the existing national disgrace. That is what worries me more than anything else."

"If the scheme fails, then it would be worse than a national disgrace, because we could have done something about it and we didn't."

Paul Watters, Head of Roads & Transport Policy at the AA Motoring Trust, said the scheme would be a great improvement and provide motorists with value for their road tax.

"It's not just about time saving," he said, "the road there is badly designed. It has been there for half a century, if not longer, so it has a reasonably high accident rate. I don't see there's any option but to do it."

Photo: as well as altering the roads around Stonehenge, the plans could potentially improve visitor access to the stones. © English Heritage.

Although he didn't want to comment on any particular proposal, he added, "Boring the 303 is probably a good thing, because it means you can give the landscape back."

While a spokesperson for the Department for Culture, Media and Sport declined to add anything further, he reiterated comments made at the launch of the scheme by then Arts Minister Tessa Blackstone.

Of the plan to bore a tunnel, Baroness Blackstone said: "It will ensure Stonehenge is reunited with its surrounding monuments in their natural downland landscape setting, protecting the site from heavy traffic, and make possible the construction of a world class visitor centre."

If enough objections are lodged with the Highways Agency before next Wednesday, a public inquiry will be held next year.

However, as a spokesperson for the organisation explained, this has already been allowed for and would not upset the project timetable, should a report find in its favour.