Concerns have been raised that Norfolk County Council is being put at "unacceptable financial risk" through its pursuit to build the Western Link.
But council leaders do not agree and say there is a "lot of support" for the £153m project, which would connect the Norwich Northern Distributor Road to the A47.
The issue of the 3.9 mile road, which would run from the A1067, near the NDR, travelling halfway between Weston Longville and Ringland, was raised at a meeting of Norfolk County Council's Conservative-controlled cabinet on Monday (April 12).
Labour councillor Emma Corlett referred to a report by Wild Wings Ecology. which says the road would pass through a nationally important area for a 'supercolony of barbastelle bats.
The Bat Conservation Trust has supported the WWE survey, saying they have “significant concerns” about the road, and the impact on bats cannot be “adequately mitigated or compensated for”.
At the meeting, Ms Corlett asked Martin Wilby, cabinet member for highways and infrastructure if he had read the statement by the Bat Conservation Trust.
And she asked: "Do you agree that this is now putting the council at unacceptable financial risk, because I cannot see how it will get through the planning process?"
Mr Wilby said he had read the report, but said: "I do not agree that this is going to put us under financial pressure.
"You've got to remember there is a lot of support for the Western Link, especially from local people to the west of Norwich, who are suffering from rat-running.
"We need better connectivity between the Broadland Northway and the A47 and this is a crucial piece of infrastructure for Norfolk."
He said the council had carried out "extensive bat surveys" over the past two years and "considerable measures" such as green bridges and underpasses would support bat populations.
The Department for Transport gave conditional support for the road last summer and the green light to proceed to the next stage of the national process.
But permission and funding has yet to be secured. The council needs to submit a business case to the government, but that has been delayed three times.
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