RBS, which is 84% owned by the taxpayer and Lloyds, which is 41% owned by the taxpayer, will now have to make £94bn available in loans to small businesses in 2010 and 2011.
At least half of this lending must be to small and medium-sized firms.
He will create a new investment corporation – called UK Finance For Growth – to oversee the support for businesses.
Darling added that the FSA must speed up the new bank licence process and added that at least five new banks are either in the market or are in the process of setting up.
HM Revenue and Customs is to open discussions with lenders on the formal introduction of an income verification service. The service would provide lenders with greater certainty about the consumers they lend to.