BATTLELINES over the future of Stonehenge were drawn this week, as a key opponent to the scheme, the National Trust, presented its case.

The charity, which owns much of the land surrounding the monuments, argues the Highways Agency's plans for a 2.1km tunnel through the World Heritage site will not be sufficient to restore tranquillity to Stonehenge and protect vital archaeological remains, and it wants the tunnel extended by 800m.

"The National Trust would not be an objector at this inquiry if the scheme that is presently proposed were acceptable," said Keith Lindblom QC.

"It congratulates the government for its desire to pursue a scheme that would rescue Stonehenge from its present predicament.

"But the scheme proposed is not the right solution.

"Stonehenge is of a stature comparable to the Pyramids, the Taj Mahal and the Great Wall of China.

"The World Heritage Convention requires the United Kingdom government to do whatever lies within its capabilities to sustain the integrity of this site. The burden could not be heavier.

"The spirit of this place has been spoiled by the roads that blemish it, by the dismal visitor facilities and by the cultivation of crops.

"There is now the opportunity to repair this harm and to restore the stones and their setting to the dignity, tranquillity and spirit of their original creation.

"Our response must not be to compromise the future of Stonehenge by repeating the mistakes of the past."

The National Trust says the tunnel's western portal must be moved 200m westwards and the eastern entrance built an additional 600m to the east, to benefit six archaeological sites, including Normanton Down barrow group.

The charity also wants the tunnel constructed by a boring machine, instead of the proposed sprayed concrete lining method, to reduce the impact at Stonehenge Bottom, and is asking for a bridleway rather than a byway to be created along the route of the former A303. These alterations would have significant effects on the timescale and cost of the project, on which work currently estimated at £200m could start as early as next spring.

A report into longer tunnels states that the earliest construction could begin on an extended tunnel would be late 2006, but Mr Lindblom said any setback would be justified.

The barrister was unable to give specific information about where the extra millions needed to lengthen the tunnel by 800m would come from bu in a statement, the National Trust said: "The Trust's remit does not extend to assessing the relative economics of one scheme against another.

"The issue of cost must be a matter for the government, having regard to its responsibilities under the World Heritage Convention."