Boris Johnson today unveiled plans to help protect small shops.
All new retail developments are to be ordered to provide cut-price rents to independent retailers.
Details of the Mayor's proposals are still being worked out but will be published as alterations to the London Plan in the next eight months.
The Mayor has already launched Planning For A Better London, which sets out some of his proposed changes and includes a commitment to ensure a diverse retail sector.
The Evening Standard has been runnning a Save Our Small Shops campaign which aims to stop the march of chain stores. Mr Johnson made the announcement at City Hall as he chaired his first business summit.
The event was attended by representatives from a range of London businesses.
He said: "During the election I promised to champion all sectors of London's business community and especially look out for the concerns of small businesses. Our small shops add real character and diversity to the capital's high streets but they are finding themselves squeezed out by competition from supermarkets and rising unsustainable rents.
"My proposals aim to help reverse this trend, offering small retailers the opportunity to make a success of their enterprise both by making more suitablepremises available and taking steps to level the playing field by securing affordable rents."
Stephen Alambritis, of the Federation of Small Business, said: "New retail developments will always be springing up in London. The key is to ensure that small businesses are part and parcel of those shopping sites. By emphasising the need for suitable premises and affordable rents, Boris Johnson is definitely travelling in the right direction."
The announcement of the plans follow a plea from Mr Johnson to Haringey council asking it to refuse planning permission for a new development which would close a popular Latin market.
The proposed re-design of Wards Corner, will lead to the closure of Pueblito Paisa market in Seven Sisters which Mr Johnson visited during his election campaign.
