The controversial Norwich Western Link scheme has been dealt a potentially significant blow, after political opponents combined to urge the government not to bankroll the £198m road.

The Conservative-controlled Norfolk County Council wants the government to pay £168m of the cost of the road, which would connect the Northern Distributor Road to the A47 to the west of Norwich.

But all opposition parties at County Hall have now united to write to the Department for Transport saying it would be an "environmentally and financially catastrophic" mistake to fund the road.

Campaigners against the scheme believe that with three political groups expressing their concerns to Whitehall, the government will get the message the project does not enjoy universal support, leaving the 3.8 mile project facing an uncertain future.

Members of the Labour, Liberal Democrat and Green groups have signed the letter, in which they say the road, which would cost £50.8m per mile:

  • Undermines national climate change objectives

  • Damages wildlife habitats

  • Risks planning failure

  • Does not represent value for money

  • Is being handled in a way which is not transparent and lacks accountability

Jamie Osborn, Green Party county councillor, said: "They claim the Norwich Western Link will bring all kinds of benefits to the county, but they have failed to provide the most basic evidence to back that up and are unwilling to answer questions.

“Instead of wasting more time and money on this reckless road, the council should be prioritising infrastructure that will bring proven environmental, economic and social benefits, like a decent bus network.”

Emma Corlett, deputy leader of the opposition Labour group, said: “This project is environmentally and financially reckless.

"Communities that are blighted by rat-running and excluded from a decent public transport network can’t wait years for what is little more than a vanity project.

"We need urgent investment in sustainable and integrated public transport that genuinely shifts journeys from private vehicles to buses, cycling or walking.”

Liberal Democrat group leader Brian Watkins has also signed the letter.

Norwich solicitor David Pett, from the Stop The Wensum Link campaign group, said: "It's important the government does hear strong opposition to the road and we have also written to the department to put our own case forward."

But Martin Wilby, Norfolk County Council's cabinet member for highways, infrastructure and transport, remains confident the council has made the case for the road to get government cash.

This summer, the council submitted a business case to the Department for Transport to secure the £168m share of the costs.

Mr Wilby said: “The outline business case uses strong evidence to set out why government investment in the Norwich Western Link is vital to Norfolk.

"As part of this we have been able to show that the project is considered high value for money according to the Department for Transport’s criteria and also that it will lead to a reduction in carbon emissions from vehicles, supporting national and regional policy.

“There are lots of checks and balances on an infrastructure project like this."

The council will lodge a planning application to its own committee and Mr Wilby said the project's environment mitigation and enhancement proposals would form part of that submission, which anyone would be able to scrutinise and comment on.

He added: "The reasons for providing the Norwich Western Link are as compelling as ever – traffic congestion is building up again following the easing of coronavirus restrictions and with significant population, housing and job growth expected in the Greater Norwich area this will continue to worsen.

"We need to provide the best solutions to the problems that exist now and prevent further congestion and road safety issues arising where we can."

Businesses, including Norwich International Airport, Chantry Place and First buses have backed the road, as have MPs, the New Anglia Local Enterprise Partnership and Norfolk Chambers of Commerce.

But it is opposed by groups such as Norfolk Wildlife Trust, Norfolk Rivers Trust, the Campaign To Protect Rural England and The Bat Conservation Trust.