A prominent campaigner for an Isham bypass says the suggested dualling of a section of the A509 between the village and Kettering would make things worse.
Plans for a 2.1m sq ft warehouse park on land near the village - which have attracted strong objections - will be considered by Kettering Council at a date to be confirmed.
In its latest consultation response Northants County Council admits the A509 doesn’t have the capacity to cope with the development without significant enhancements.
But with only two-thirds of the £38.5m needed for the Isham bypass secured, the council says dualling the A509 northbound between A14 J9 and the development site access is the “more likely scenario”.
When asked whether he thought dualling the section of the A509 would work, Isham bypass campaigner Graham Rait said: “No way.
“I think there will be a traffic bottleneck and it will do nothing for Isham.
“The traffic between the roundabouts will be worse than it is now.
“They estimate 4,000-plus vehicle movements a day with the new development and if half of those go south [through Isham village] it will be terrible.”
The scheme would need to be future proofed to allow the remainder of the Isham bypass (to the south) to connect to the initial dualled section.
The development, which could provide more than 2,000 jobs, would not be allowed to start until highways improvements had been completed.
Developers DB Symmetry would be required to pay a minimum contribution of £3m towards any highways scheme.
But Mr Rait says the fact the bypass has not yet been properly funded is demoralising.
He said: “We had a meeting with DB Symmetry and they clearly want a bypass.
“They want a bypass, we want a bypass, everyone wants a bypass but because of the funding gap it’s not happening yet.
“It does get a bit demoralising.
“Every time we take a step forward we take a step back.”
Former county council leader Jim Harker – who lobbied for the Geddington bypass during his time in charge at the authority – urged all parties involved to put renewed effort and financial support into the bypass.
A spokesman for Northamptonshire County Council said the Isham bypass is a ‘priority scheme’.
The spokesman said: “Not only will it help benefit economic growth in the county but it will also bring much needed relief to the village of Isham.
“The design of the scheme has been determined for some time.
“At present, £25m funding towards the current £38.5m cost of the scheme has been secured through the government’s Growth Deal.
“We are looking at a variety of options to bridge the funding gap and would consider all funding possibilities as and when opportunities arise.”