Harris released the information in the form of a written parliamentary statement yesterday. "The Government announced in 2005 that it planned to commission a review of options for the A303 Stonehenge improvement after a substantial increase in the estimated cost of the proposed 2.1 km bored tunnel scheme," he wrote.
"The approved budget for the scheme when it was taken to public inquiry in 2004 was £223 million. The latest reported cost estimate is £540 million which reflects a number of factors including unexpectedly poor ground conditions, more stringent requirements for tunnelling work and rapid inflation in construction costs.
"The review identified a shortlist of possible options, including routes to the north and south of Stonehenge. After careful consideration we have now concluded that due to significant environmental constraints across the whole of the world heritage site, there are no acceptable alternatives to the 2.1 km bored tunnel scheme.
"However, when set against our wider objectives and priorities, we have concluded that allocating more than £500M for the implementation of this scheme cannot be justified and would not represent best use of taxpayers' money."
Reactions to the decision were swift and prompted the Speaker of the House of Commons to grant shadow transport secretary Theresa Villiers an urgent question.
"Labour has had 10 years to sort out this problem and has failed completely. Now it looks like a solution is further away than ever despite £23M having been spent on preparations for a tunnel which is no longer going to be built," she said.
"We are seeing more broken promises on roads and yet another let down for thousands of people frustrated by congestion on the A303. The Government's complete failure to tackle this problem is becoming a national embarrassment. Its decade of indecision is impacting on road improvements and planning applications for towns as far away as Penzance, and could jeopardise Stonehenge's World Heritage status."
The RAC Foundation also condemned the move. David Holmes, chairman of the Foundation, said: "A price should not be put on our heritage in this way. We are extremely disappointed that the Government has condemned Stonehenge to further environmental damage and the A303 to chronic congestion due to their failure to act. Our report, 'Roads and Reality' clearly states that the problem of congestion will not go away. Years of misery lie ahead."
The Liberal Democrats were no less scathing, arts and culture Spokesperson Dan Rogerson said, "After a decade of dither and delay, the Government has opted to neglect the single most important historic site in the United Kingdom. Today's decision will not just cause extra congestion and frustration on the A303. It puts a UNESCO World Heritage site at risk of damage from the ever-increasing volume of traffic.
"The thousands of tourists we hope will visit Stonehenge during the 2012 Olympics will now see the site blighted by the route of a major road. Worse still, the minister wants to brush this off by labelling the cancelled scheme as 'regional'. Stonehenge is of national and international significance, and should be treated as such."
However, the environmental lobby were delighted, Friends of the Earth's South West campaigner Mike Birkin said, "This is great news for the future of the Stonehenge World Heritage Site. This road would have encouraged more traffic on to our roads and damaged one of the most precious archaeological sites on the planet.
"Hopefully today's decision will also kill off plans to dual the A303 along its entire length. We must invest in low-carbon, sustainable alternatives to the nation's transport problems," he said.