A coalition of environmental groups is urging people against the controversial Norwich Western Link to join forces to stop the £274m scheme.

The campaigners warn the 3.9-mile road, to the west of Norwich, would poses a "grave threat" to "irreplaceable nature" in the area.

Norfolk County Council's own documents confirm the road, which would link the A47 near Honingham to the Norwich Western Link, will have "significant adverse effects" on some 300 acres of countryside.

And the coalition is opposing the road, which includes a viaduct, on the grounds of the unacceptable impact on wildlife and the wider landscape in the Wensum Valley.

Woodland along the route of the Norwich Western LinkWoodland along the route of the Norwich Western Link (Image: Rachael Murray)

Members of the coalition include Norfolk Wildlife Trust, Stop the Wensum Link, CPRE Norfolk, Norwich Friends of the Earth, the Woodland Trust, Norfolk and Norwich Naturalists' Society, Buglife, Norfolk and Norwich Bat Group and the British Dragonfly Society.

Mike Jones, from the Norfolk Wildlife TrustMike Jones, from the Norfolk Wildlife Trust (Image: Norfolk Wildlife Trust)

Mike Jones, from Norfolk Wildlife Trust and a spokesman for the coalition, said: "The harm a development like this would do to this rare and irreplaceable landscape cannot be overstated. 

"In addition to the land forever lost to the wide swathe of concrete cutting across the landscape, the road will also scar a significant area around it.

"The noise of traffic will drown out birds as they attempt to communicate. Light pollution will ruin the hearts of woods nearby, rendering them unsuitable to nocturnal species dependent on the darkness.

A barbastelle batA barbastelle bat (Image: C. Packman)

"Species such as owls, bats and badgers will be condemned to collisions with cars as they continue to use what remains of the landscape they are dependent on for everything.

“The damage it will do is irreparable and giving permission to these plans will set a precedent, leading to more development on protected habitats in other parts of the UK in future."

The coalition has created an online tool for people to collectively lodge objections and is encouraging people to use it at www.norfolkwildlifetrust.org.uk/nwl

Campaigners against the Norwich Western LinkCampaigners against the Norwich Western Link (Image: Archant)

Natural England told the council that, based on the information the authority has provided so far, it would be unlikely to award a licence needed to do anything which might disturb or harm rare barbastelle bats on the route.

But the council has pressed ahead with lodging plans for the road with its own planning committee, although there are calls for a planning inspector to take the decision out of the hands of councillors.

The road has long been a priority for Conservative-controlled Norfolk County Council.

Council leaders have said the road will cut congestion in villages such as Weston Longville and Hockering, which suffer from rat-running.

They have said it is crucial for the county, would speed up journey times and would bring an economic boost for businesses.

Norfolk County Council's County Hall headquartersNorfolk County Council's County Hall headquarters (Image: Mike Page)

The council has said its plans include mitigation measures which would protect wildlife and stop pollution in the River Wensum.

A Norfolk County Council spokeswoman said: "We are currently in the planning stage of the project and we will continue to work with the planning authority to respond to the matters that have been raised by consultees.

"We would encourage anyone interested in the Norwich Western Link to look through the planning application documents and provide any comments through the planning authority’s consultation so that these can be considered."

The Department for Transport has agreed to contribute £213m towards the road's bill.

Tories at County Hall hoped the government would increase that to £251m, using money 'saved' by cancelling the northern leg of the HS2 rail route.

But the government failed to confirm any extra cash before the General Election was called.

People can see and comment on plans for the road via https://norwichwesternlink.oc2.uk/document/7 until Thursday, July 18.