A residents association believes a historic piece on land in Elmers End is under threat and want to register it as a town or village green.
The land, named Elmers End Green, is flanked by Croydon Road and Upper Elmers End Road, not far from South Norwood Country Park.
West Beckenham Residents’ Association (WBRA) want to see it granted the status to protect it from alleged commercial development.
The group claims the toilet block in the centre of the site could be sold off for advertising.
In response WBRA is putting forward an application to Bromley Council on Wednesday July 9 under the Commons Act 2006.
Marie Pender, 64, from Elmers End Road, says residents are worried a “favourite” part of the community is going to be lost.
She said: “We want to register Elmers End Green because we love it. It is the focal point of a suburban area of housing and shops and is our green lung and open space.
“We enjoy seeing it, walking on it, and looking out onto it from the many restaurants and cafes that surround it.
“It was a great shock in summer 2013 to find Bromley wanted to sell off the toilet block land”.
The former civil servant said in 1998 resident pitched together to pay for a village sign to be erected and for trees to be planted on the green.
She added Elmers End Green, currently a designated ‘urban open space’, can be traced back to 1723 and has stood unchanged for around 300 years.
Bromley Council responded: “There is no threat to the grassed area of Elmers End Green and never has been.
"The closed toilet block has now been leased and it is up to the owner what to do with it, which is of course subject to planning permission and consultation in the usual way, if such an application is submitted.
"In common with our sponsorship schemes elsewhere in the borough, small advertising signs can be erected to subsidise the cost of maintaining the flowerbeds and of course these signs are subject to planning permission which has been refused on this occasion at this location.
"It would be inappropriate to comment on the Village Green application as a decision will be made about this very shortly”.