A druid who calls himself “King John” said he'll take the Government to the High Court if an underground tunnel near Stonehenge gets the go-ahead.
Highways England is planning to bury the A303 road - which currently runs south of the UNESCO world heritage site - as part of a £1.6bn project.
The plans were submitted in November 2018 and are currently being examined by the Government planning inspectorate.
The agency will then give a recommendation to Secretary of State for Transport, Chris Grayling, who will make the final decision.
Druid John Collis - who calls himself King John - has announced if the plans get the green light, he'll appeal to the High Court for a judicial review.
Mr Collis, 44, from Oxford, said the Government "should be ashamed of themselves".
He added: "Stonehenge is an ancient site which many of us druids respect and worship.
"We need to protect this ancient site from being ripped apart and destroyed by greedy government developers who are in the process of examining the plans.
"We pray, meditate and worship at the stones which are very sacred and need to be respected.
"If the Government and an independent planning inspector are not going to listen, then we will take the action to the court.
"They are fools and should be ashamed of themselves.
"They are disrespecting a tribute to our ancestors which has been there for centuries on end.
"There are also still lots of untold stories and archaeological finds at Stonehenge which are yet to be uncovered the site should be kept as it is.
"On our calendar, we regularly have solar and lunar ceremonies at the heritage site
as well as give special services during the solstices and equinoxes."
'Pilgrimages to Stonehenge for our moon ceremonies'
Map showing the position of the proposed tunnel alongside Stonehenge. Image: Richard Percival/SWNS.
The Druid Order of Avebury also has concerns and a spokesman said members were worried the tunnel will negatively impact Blick Mead, a nearby series of ancient natural springs.
He said the water at the 4000 BC site is special and should remain "untouched".
In a statement, they added: "We would like to make sure that all the landscape neolithic findings are to be reported and not be interfered with during any tunnel diggings.
"As well as this, byways along the A303 accesses should remain open for our safe pilgrimages to Stonehenge for our moon ceremonies, for full, and dark moon services."
Proposals for a tunnel below Stonehenge were first suggested in 1995, but were reintroduced by John Glen, MP for Salisbury in 2014 as part of a wider plan to upgrade the A303 to a dual carriageway.
Later that year the coalition Government gave support for a 1.8-mile tunnel near the ancient site.
Highways England claim the plans will benefit the World Heritage Site by restoring tranquillity.
It claims it would boost the economy by providing an effective transport link and reducing the traffic blight on local communities.
A spokesman for the Planning Inspectorate said: “The application for the A303 at Stonehenge was accepted for examination by the Planning Inspectorate on 16 November 2018.
"There are many opportunities for people who may be affected by the proposed project to give their views both during the developer’s public consultation and during the Planning Inspectorate’s examination of the application.
"Following the examination the Planning Inspectorate will make a recommendation to the Secretary of State for Transport who will make the decision whether to grant development consent or not.
"There follows a period of six weeks during which the Secretary of State’s decision can be challenged in the High Court.”