Britain's famous Stonehenge landmark [Photo/VCG]

Grayling says: "This major investment in the southwest will provide a huge boost for the region and unlock growth in the tourism industry."

He says the scheme will also support 120,000 extra jobs and 100,000 new homes across the region.

Highways England chief executive Jim O'Sullivan says: "This scheme will enhance, protect and restore tranquillity to one of the UK's most iconic landscapes."

The agency says its original plans had been modified after listening to heritage groups, archaeologists, historians and engineers. This has included moving the position of one of the tunnel entrances to avoid conflicting with the solstice alignment.

"The route ensures the Stonehenge World Heritage site will be protected and enhanced for people from across the world to enjoy," says the transport department.

UK Secretary of State for Culture, Karen Bradley says: "Stonehenge has captured the imagination of people around the world for centuries and is a site of global importance. With over 1 million visitors a year it is one of the jewels in the UK's crown and it is important that we preserve it for generations to come. This investment will help make the visitor experience much more enjoyable."