A date has been set for a public inquiry into the Grantham Southern Relief Road.
The Department for Transport confirmed the date as Tuesday, December 4 at the Jubilee Church Life Centre, Grantham.
Lincolnshire County Council have expressed their “disappointment” at the announcement.
Councillor Richard Davies, executive member for highways, said: “In the end we were successful in getting one of the five objections withdrawn about environment concerns from a member of the public.
“However despite our best efforts we haven’t been able to reach agreements with Network Rail, Zurich, Grantham Motor Company and Western Power Distribution in time to avoid an inquiry.
“As a result, we’ll be stating our case for Grantham’s southern relief road starting on 4 December.”
An inquiry will last up to six days and is designed to provide a robust scrutiny of all aspects on the project.
The £81 million project is still expected to go ahead, looking to link the A52 at Somerby Hill to the A1.
Mr Davies added: “We’d hoped a public inquiry wouldn’t be necessary, but here we are. I’m confident that work on the rest of the relief road will start in early 2019.
“The biggest problem with the situation is that none of what we’re talking about doing is a surprise, particularly for Network Rail.
“I think everyone agrees that the relief road is an absolute necessity, and it’s disappointing that a taxpayer-funded service can have such a detrimental effect on getting it built.”