Jenny Jones, Green party candidate for Mayor, says she would work to bring empty homes back into use if elected next month.
On Monday Ms Jones will visit Southwark to meet local residents and discuss local housing needs.
Figures issued by the Green campaign suggest in 2010 there were 3,367 empty homes in the borough.
In her manifesto Jones has promised to offer empty homes owned by the Greater London Authority to groups who work with homeless people to bring them back into use.
She has also committed herself to set up a clearinghouse to offer all publicly owned derelict land to Community Land Trusts.
Ahead of her visit Ms Jones said: “London is facing a housing crisis that decision-makers have been only too willing to ignore. We want to change the housing market from a playground for speculative investment to a source of secure, affordable homes.
“If we are to ensure that residents of the capital can house their families and themselves, slow the continuous rent increases, reduce homelessness and end the insecurity that many tenants suffer, then City Hall must act decisively.”
Candidates for Mayor include Jenny Jones (Green party), Ken Livingstone (Labour), Lawrence Webb (UKIP) Boris Johnson (Conservative) and Brian Paddick (Liberal Democrat). A full list of candidates can be found here.