The disused twin-track railway tunnel between Charwelton and Upper Catesby is set to be transformed into a vehicle testing facility with Daventry District Council expected to approve a planning application.
The 2.7km underground stretch of railroad will be used for aero-acoustic tests and an associated technology park on the site of the former Charwelton Station will be constructed.
The proposal will see the tunnel sealed, potentially operational on a 24-hour seven day-a-week basis and made available to interested parties from the motor or motor racing industries to rent on a commercial basis.
Many third parties have expressed concerns regarding the remote location of the site and the likely visual and environmental impacts of the unusual scheme.
Planning policy is generally opposed to new medium to large-scale isolated commercial development within the open countryside.
The likes of the Charwelton Neighbourhood Forum and parishioners, the Northamptonshire Wildlife Trust and Northamtonshire Bat Group have registered their objections to the plans.