Controversial plans for a road tunnel near Stonehenge have been finalised, with campaigners opposing the development claiming it would cause "irreparable damage" to the surrounding landscape.

The plan, which has been created to ease traffic congestion around the ancient site, would see the a new four-lane 1.8m (2.9km) tunnel built, which the Department for Transport says would remove the sight and sound of traffic from the famous monument.

Among Britain’s top tourist attractions, Stonehenge welcomes more than 1.3 million visitors annually but is only accessible by a series of small country roads linking London with the southwest. The stretch of road nearest to Stonehenge is a single-lane, which creates extensive traffic jams sometimes stretching back several miles as drivers slow down to get a look at the heritage site in passing.

The plans were first touted around three decades ago, but have been put on the shelf multiple times with concerns over environmental damage.

The Stonehenge Alliance – the main body opposing the £2bn (US$2.4bn, €2.3bn) roadworks – say “permanent harm” would be done to a landscape “considered the most archaeologically significant land surface in Europe without parallel.”

“All archaeology in the construction zones would be destroyed and the A303 would become the largest ever human intervention in an area fashioned and revered by over a hundred generations of our ancestors,” said the Alliance in a statement on a petition opposing the plans, which has more than 22,000 signatures.

“The whole Stonehenge landscape has an outstanding universal value that is of immense significance for all people for all time, and this transcends any consideration of sorting out a 21st century part-time traffic jam.”

Unesco, which designated Stonehenge a World Heritage Site in 1986, has said it is monitoring the development “according to the Operational Guidelines for the Implementation of the World Heritage Convention”, adding that it has been “fully informed of concerns raised” in regards to the major development. A report by Unesco and the International Council on Monuments and Sites has also recognised the benefits of the project.

English Heritage and the National Trust have also given their support to the option of "the longest tunnel possible” – meaning it would cost more but avoid archeological damage. A public consultation to get the views of drivers and residents will run until 5 March.