Rock Common Quarry has been operated by the firm Dudman under lease from landowners The Wiston Estate for the past 10 years.
Now both are seeking planning approval from West Sussex County Council to extend the time permitted for sand extraction and to change restoration plans for the site.
Initially they had planned to create a lake by filling the empty quarry with deep water - but now want to fill it with builders’ rubble instead.
Chanctonbury Landfill Action Group say: “This is not restoration, it is landfill.”
Hundreds of villagers have lodged objections with the county council.
Meanwhile action group members gathered with placards and protest banners outside Wiston Village Hall on Friday where Dudman and the Wiston Estates were holding a presentation of their proposals.
Action group chairman Russ Fowler said that many felt they had been misled by the proposals. He said documents “clearly show they intend to fill the quarry to the top, which will take 50 years plus to complete.”
There are also fears that the works could lead to ground water contamination.