Mayfield Market Towns wants to build the complex in the villages of Twineham and Wineham and parts of neighbouring Woodmancote, Albourne and Shermanbury.
They say it would meet a long-term housing need in the area, but opponents including CPRE Sussex and the Locals Against Mayfield Building Sprawl (LAMBS) say the area is liable to flooding and should be preserved for the public to enjoy.
The protest was in advance of the public meeting held jointly by LAMBS and CPRE Sussex on 18 October.
