Transport chiefs have asked council planners for more time to assess the impact of proposals to build 2,500 homes on the outskirts of Inverness.
It emerged last week that a scheme to construct a new town at Stratton had been resurrected, with the developer keen to start work next year.
Almost 200 acres of land between the existing A96 Aberdeen road and the communities of Culloden and Smithton has been earmarked for the project.
It would feature a new town centre, retail park, a primary school, health centre, park-and-ride facility and hotel.
A masterplan for the new town was approved by councillors in 2010 but the scheme has now been “re-jigged” so that the first phase will start with 400 homes, rather than a new supermarket as originally envisaged.
Highland Council’s own land contamination unit has already responded to the new development brief, recommending that five conditions be attached to any planning consent.
In a letter to the planning department, officials said part of the site was once used for fuel storage by Stratton Farm and that “may have resulted in land contamination”.
Transport Scotland has also responded to the development brief, saying it will be unable to assess the implications of the scheme on the A96 Aberdeen road within the allotted timescale, and that it may have to recommend it is rejected unless an extension is granted.
John McDonald, from the agency, wrote “I am currently assessing the implications of the planning application on the trunk road but will not be able to respond within the normal timescale.
“I should therefore be obliged if you would extend the consultation period until this process is completed.”
Under the plans, the first 400 homes would be followed by seven other sections as part of the first phase of the 20-year scheme.
The proposed schedule of work involves construction of a further 150 affordable homes, followed by a 13,000sq ft supermarket, an 80-bed hotel, restaurant and pub, another 30,000sq ft supermarket, an 18,000sq ft non-food store, a 43,000sq ft supermarket and a 150-space park-and-ride facility.
As originally envisaged, there would also be a health centre, a church, a community centre, offices and a new primary school.