Cambridgeshire County Council has invited expressions of interest from contractors wanting to build the new Ely Southern Bypass, which could create hundreds of new jobs.
The £35 million project has already achieved planning permission, with the main contract worth £25 million.
It will link the A142 at Angel Drove to Stuntney causeway, with a new bridge over the railway, as well as a 500 m-long viaduct over the Great River Ouse and its floodplain.
The bypass will be 1.7 km long and the companies who prequalify will be vying for a job on which work is expected to commence work in August.
At present, traffic using the A142 to travel east or west of the city has to pass through the historic city centre, crossing the Great River Ouse near the city's railway station.
The new bypass will make the route much shorter and quicker for motorists and ease city centre congestion.
