Residents in Hill Head have been deeply angered by an application to erect a two metre fence round part of the open space between Springfield Way, Dallington Close and Mulberry Avenue.
The green has been enjoyed by everyone for decades since the estate was built, but there are reports that part of the land was recently sold at auction.
Agents for the applicants say they want the fence to prevent vandalism, anti-social behaviour and fly-tipping, which would be to the detriment of the area.
Councillor Jim Forrest says: "I don't recall any of these issues arising in this space in the 25 years I've lived in Hill Head. A fence would be of permanent detriment to the area, destroying the view and preventing lawful use.
"This explanation insults residents' intelligence."
Jim, who is Lib Dem spokesman on planning and development, adds: "This could have worying implications for Fareham as a whole. I will be making inquiries about the sale of this land and about planning agreements relating to it.
"Residents should be entitled to a clear picture of whether land around them is public open space, or just permissive space which can be closed off."