An animal protection group is calling for a bypass to be closed just weeks after it opened to ensure the safety of nearby badgers.
It is estimated about 3,000 meters of fencing is not in place
The A6 Rothwell-Desborough bypass in Northamptonshire was formally opened by transport minister David Jamieson on 14 August to ease traffic congestion.
But the North Northamptonshire Badger Groups (NNBG) claim one badger has already been killed on the road.
The group said fencing and badger tunnels, which were to be put along the entire 6km stretch of road, are not in place or unusable.
Richard Turner, spokesman for the NNBG, said: "We have been working with the Highways Agency and its contractors for 12 years to ensure the badgers would have their safety guaranteed.
"It is a waste of public money spent on this project if the Highways Agency opened the bypass without checking the fencing was complete and the tunnels useable."
The NNBG and the National Federation of Badger Groups are writing to Mr Jamieson asking for the bypass be closed until the safety measures are completed.
About 2,600 badgers have been killed on county roads in 12 years.
A statement from the Highways Agency said: "At the opening of the road all the tunnels and a significant amount of the badger fencing was in place.
"There were unfortunately some sections that were not complete at opening due to lack of a specialist contractor to complete the works.
"However, there are currently three teams of workers on site installing the remaining sections of fencing which will be completed by the end of this week."
It added: "It is very unfortunate a badger has been killed on this stretch of the road.
"It is very difficult to predict how the wildlife moves and we cannot ensure they won't choose to use a different section of the route where no fencing has been provided.
"As with any road we cannot guarantee badgers will not be killed on the bypass but we do hope to minimise the number deaths."