The procurement process for a £200m bypass near Manchester has been delayed after it emerged the project may have to go back out to public consultation.
Eight construction firms are understood to be in the running to build the A556 bypass between Junction 19 of the M6 and Junction 7 of the M56.
The firms have filled out pre-qualification questionnaires and had hoped to have received their tender documents by now.
But the project, to build 5 km of new dual carriageway and widen 5 km of existing road, has hit an obstacle. The Highways Agency needs to include an extra 600 m of road, encompassing the M6 roundabout, which was not initially included in the approved scheme.
The original plan won 83 per cent backing from the public at a consultation six months ago, as well as getting the seal of approval from the transport secretary.
Officials had expected the roundabout to be improved as part of a £2.9 billion project to widen the M6 along a 51-mile stretch between Birmingham and Manchester. However, it has now been switched to the bypass scheme.
A spokeswoman for the Highways Agency said: “Without this delay we would have been going out to tender by now.
“But you have to do things the right way. This latest bit of the road was not consulted on and we will talk to the public about it in due course.
“As a matter of urgency we are in the process of drawing up a shortlist and hope to invite tenders later this summer.”
Firms understood to have put their names forward are Balfour Beatty, Skanska, Carillion, Ferrovial, Bam Nuttall, Costain, Laing O’Rourke and Vinci Construction Grands Projets.
The Highways Agency anticipates the job will cost between £142m and £207m, and take just over six years to complete.
The A556 is a major trunk road between North Cheshire and South Manchester, currently carrying around 50,000 vehicles a day, nearly a fifth of which are HGVs..
The section of the A556 under consideration is between the M6 junction 19 near Tabley/Knutsford and the M56 junction 7 near Bowdon.
The project is expected to be relatively complex given its proximity to two major motorways and Manchester city centre.
Overbridges, underbridges and culverts also feature in the scheme.