Boris Johnson says he wants to put pressure on the building industry to increase the amount of affordable homes in London. The mayor was heavily criticised in 2008 when he scrapped a quota forcing developers to make half of all new homes affordable.
The mayor believes the economic recovery and the boom in the housing market should force developers to rethink their commitment to social housing.
The mayor also criticised the lack of low-costs homes in a planned development on the Royal Mail site at Mount Pleasant. The proposal to build 700 homes has been "called in" by the mayor.
But the mayor ruled out bringing back the 50% rule, saying it was "economically undeliverable."
He also told ITV News he does not think overseas investors are fuelling London's housing crisis.