Fresh environmental fears over a potential new road joining the Northern Distributor Road to the A47 have been raised with senior councillors at County Hall.
The much-debated Norwich Western Link is proposed to connect the NDR - now known as the Broadland Northway - with the A47 at Honingham, passing across the wildlife-rich Wensum Valley.
Last week, Norfolk County Council submitted its first business case for the road to Transport England. However, it still faces opposition over the environmental viability of the project.
The council's cabinet yesterday faced a string of further questions around the link's potential impact on the climate; including from the owner of a wooded area which would make way should the road be built.
Iain Robinson, a lecturer at the University of East Anglia, is the owner of three acres of woodland near Ringland, which stands to be felled should the road go ahead.
In a question submitted to the council, Dr Robinson asked: "A mature oak in my woodland can support over 200 species of insect, which in turn support bird and mammal life.
"Can the councillors explain to me how they will manage to create a net biodiversity gain when habitat that has taken over 200 years to mature will be destroyed."
In his written response, council leader Andrew Proctor said: "The habitats created to compensate for the loss of habitats to be impacted by the preferred route will include new woodland and wetland, with measures designed to benefit the barbastelle bat and other protected species."
Another of the project's critics, Christopher Keene, questioned how building a new road would help the council reduce carbon emissions in the county.
In his response, Mr Proctor said the link would result in a reduction in the number of miles vehicles travel, which would result in a reduction of emissions.
Martin Wilby, cabinet member for transport, added: "One thing that will improve things in years to come is the ambition for greater electric vehicle use - so there are big improvements to be made."
A similar question was also asked by Jenn Parkhouse, chairman of the Wensum Valley Alliance, alleging the road would result in a 20pc increase in carbon emissions; though the council insisted its aim is to result in a 4pc reduction.
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