Southwark Peabody tenants have staged a protest outside the Peabody Trust headquarters in Westminster Bridge Road.
The tenants are also concerned about a move to market renting and claim that every flat which becomes available appears goes to market rent.
Protest organiser Dorothy Bates debating the issues with Peabody Trust director of residents' services Sally Harvey on BBC London News
"The additional rent from from market rent units across all estates, where we use this tenure, makes an important contribution to meet the Trust's costs" says estate strategy manager Mary Popham.
"It is a sad irony that we have to sell homes," said chief executive Steve Howlett.
Meanwhile several vacant flats in Marshalsea Road's Douglas Flats block are being advertised by residential auctioneers.