It is claimed plans to build a motorway between Limerick and Cork will hurt the regions and is not the right approach.
The project will be included in the National Planning Framework - due to be unveiled by the Taoiseach on Friday.
Edgar Morgenroth is a Professor of Economics at Dublin City University, he says money should be spent in Cork and Limerick - rather than a motorway connecting the two.
He said: "People end up having to commute in, there is no new economic activity in the towns along the motorway, it often bypasses them anyway and what we get is sprawl in terms of population.
"We don't get any scale in terms of the size of Cork and Limerick."