East Sussex County Council issued the warning after a number of recent incidents where material was dumped along the route of the new road.
The council is warning that fly tipping is an offence under the Environmental Protection Act and carries a two-year prison sentence and an unlimited fine.
Bob Pape, the county council’s Link Road project manager, said: “Some people seem to think it is acceptable to throw their unwanted items onto the site but this is not the case.
“Fly tipping adds to the cost of the Link Road project as our contractors are the ones who end up having to clear up their mess.”
The council will pass on any reports of fly tipping to Rother District Council, the authority responsible for dealing with fly tipping.
Fly tipping can be reported at http://eastsussex.fixmystreet.com or by calling Rother District Council on 01424 787000.