A two-mile road tunnel past Stonehenge could cost £250,000 per metre of road – as it is revealed costs so far amount to £166m.

The scheme, which was approved by the previous Conservative government, has been met with a number of legal challenges from Save Stonehenge World Heritage Site (SSWHS), says the BBC.

A Freedom of Information request showed the total planning spend up to the end of May was £166,230,578.

The BBC has been told that £287,605 of public money has so far been spent on legal fees. John Adams, chair of Stonehenge Alliance, said it would “make it arguably one of the most expensive roads in the world”.

National Highways, who said the tunnel will remove the sight and sound of traffic passing the historic site, contracted Wessex Archaeology to search the proposed route, focused largely on the two tunnel portals within the World Heritage Site.

It hired more than 100 archaeologists, in a contract costing £4.6m to date, to start a year of digging from last spring but the work was halted because of the latest legal challenge.

SSWHS argues that cancelling the tunnel scheme would save “at least £2.5bn”, having already cost £160m in the planning phase.

(Pic – National Highways)