Responding to a question from Lonndon Assembly Member Elizabeth Howlett during Mayor's question time, Livingstone said that both the East London Line extension and Crossrail's second line are in Transport for London's plan.
He went on to say that funding should be assured by 2010.
Howlett, Assembly Member for Merton and Wandsworth said, "My constituents are in desperate need for the extension of the East London Line west of the City to stations such as Clapham Junction as well as the benefits that Crossrail Two will bring.
"Without them we are left with the worst connections into central London. I have long campaigned for these transport links. The Mayor's commitment to push ahead with these projects will be welcomed by my constituents.
"Time and again we have been let down by this zone one Mayor, I hope this time he keeps his word. Whilst I welcome Crossrail, it should not be to the detriment of the services that my constituents need," she said.