The troubled £274m Norwich Western Link has been dealt a further blow - with the government's environmental advisors calling for the road to be rejected.

Natural England has objected to Norfolk County Council's plans for the 3.9-mile-road because of its impact on protected barbastelle bats.

Conservative leaders at County Hall said the organisation's objection was "disappointing", but critics said it should be the "final nail in the coffin" for the controversial scheme.

What does Natural England say?

Natural England previously signalled it was unlikely to award a licence to move or harm the bats.

Natural England says the Norwich Western Link will harm barbastelle batsNatural England says the Norwich Western Link will harm barbastelle bats (Image: C. Packman)

Without such as licence, the road, to connect the Northern Distributor Road to the A47 near Honingham, could not be built.

Council bosses hoped providing further information on mitigation measures could alleviate concerns, but Natural England officers have not been swayed.

The organisation has objected to the council's plans because of the "significant adverse effect on the nationally important population of barbastelle bats".

A visualisation of the Norwich Western LinkA visualisation of the Norwich Western Link (Image: Newsquest)

In its planning consultation response, officers stated: "Based on the information and evidence that Natural England has assessed to date, we do not consider it is possible to effectively mitigate/compensate the impacts of the proposed scheme on this barbastelle bat population, which is of national importance."

The organisation said the road would trigger a decline in the barbastelle bat population, with maternity roosts threatened, foraging habitats damaged and bats at risk of being hit by vehicles.

While the council said green bridges, underpasses and habitat creation would reduce the impact, Natural England said those would take time and there was "a lack of evidence" they would work.

The organisation also said the project, which includes a viaduct over the River Wensum, could also have "potentially significant impacts" on the River Wensum Special Area of Conservation (SAC), River Wensum Site of Special Scientific Interest (SSSI), Norfolk Valley Fens SAC, Potter and Scarning Fens, East Dereham SSSI and Alderford Common SSSI.

Natural England said it needed further information about air quality and the removal of soil, which it feared could damage the Wensum's floodplain.

The organisation said: "Without this information, Natural England may also need to object to the proposal due to impacts on some of these designated sites in addition to the objection regarding barbastelle bats."

Graham Plant, Norfolk County Council cabinet member for highways, transport and infrastructureGraham Plant, Norfolk County Council cabinet member for highways, transport and infrastructure (Image: Norfolk County Council)

What is the council's response?

Graham Plant, the council's cabinet member for highways, infrastructure and transport, said: "We have continued to discuss our proposals for the Norwich Western Link with Natural England over the last few months.

"While we have managed to resolve some of the points Natural England raised in March, others remain unresolved, which is disappointing given the scale of mitigation measures included in our proposals."

Mr Plant said the Western Link would improve safety, cut journey times and prevent rat-running through villages.

He said: "We will need some time to consider the consultation response from Natural England, alongside all the other feedback provided through the consultation, and we will continue to work with the planning authority to respond to issues raised by consultees."

James Marshall, Natural England deputy director for Norfolk and Suffolk, said: "Natural England is clear that development and nature can go hand in hand and are committed to making that happen.

"But that includes ensuring our most precious wildlife is protected from irreversible harm.

"Barbastelle bats are incredibly rare and are found only in mature woodland that can’t be recreated elsewhere.

"The proposed route for the Norwich Western Link road would destroy one of the largest remaining populations in the UK.

"It is Natural England’s duty to uphold the law designed to protect rare species.

"We cannot see how the proposed road would not destroy the bats’ habitat even if there was mitigation in place, so we have objected to this planning application,  which will also risk harm to important wildlife sites.

"We have worked closely with Norfolk County Council for more than four years on the proposed Norwich Western Link road and consistently advised on our significant concerns.

"It is now for Norfolk County Council to decide whether to grant planning permission."

Steve MorphewSteve Morphew (Image: Denise Bradley)

Steve Morphew, leader of the Labour group at County Hall, said: "Natural England have made it very clear that this road is too environmentally damaging and costly in every sense. This should be the final nail in the coffin."

Troubled times for controversial scheme

Earlier this month, Natural England designated North Wood, on the route of the road between Ringland and Weston Longville, as ancient woodland.

North WoodNorth Wood (Image: Iain Robinson)

Campaigners, including from Norfolk Wildlife Trust, said that further demonstrated why the road should not be built.

If the road does go ahead the council would need to borrow millions.

While the Department for Transport has agreed to contribute £213m towards the road's bill, council leaders hoped that would be hiked 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.

And, in response to a parliamentary question from Norwich South MP Clive Lewis, Labour ministers said they will look at alternative options to the road.