An M4 relief road around Newport would devastate wildlife say environmental groups as they step up protests.
Wildlife charity RSPB Cymru, which protested with campaign group CALM on Monday, says the so-called ‘black route’ across the Gwent Levels would destroy habitats which are home to rare species.
A public consultation is taking place, with the Welsh Government saying a relief road is needed because the current M4 motorway is not fit for purpose, and business organisations saying it would cut congestion.
If the road goes ahead, work on the £1.3bn project would begin in 2021.
However, RSPB Cymru is campaigning for the Welsh Government to stop the plans saying the common crane bird and the shrill carder bee are at particular risk.
Natasha Yorke-Dedgell from the organisation said they were “seriously concerned” about the road which would cut across “irreplaceable habitats”.
She added: “It would decimate the wildlife.”
She said the cranes had recently nested for the first time in over 400 years on the Gwent Levels and the shrill carder bee is one of the rarest bumble bees in the UK.
Ms Yorke-Dedgell added: “The carder bee only has five strong populations left in the UK.
“The other strong populations are also threatened by road diversions. The combination of these two road developments could wipe out the species in the UK.”
Meanwhile CALM said a new road would generate “huge amounts” of carbon dioxide which conflicts with a Welsh Government plan to remove carbon dioxide from energy sources, commonly known as the Decarbonisation Programme.
In a statement CALM activist, Catherine Linstrum, added: “This legislation requires us to act in recognition of the needs of future generations and not just our current selfish wants.
“We must avoid ruinous levels of global warming.”
CJS News has asked the Welsh Government to comment.