An orbital service will play a key role in London 2012
London's mayor is urging the government to meet concerns of south Londoners over local rail links when a new £6bn upgrade in the area is completed.
Under the plans, it is proposed to withdraw the South London Line service between Victoria and London Bridge.
The government decided to close the route in favour of further extending the East London Line, saying more south Londoners would ultimately benefit.
The mayor is meeting transport minister Sadiq Khan for talks on Wednesday.
Over the next seven years more than £6bn will be spent on improvements in rail services in south London, including the upgrade and extension of the East London Line to complete an orbital London Overground service in the capital.
Thameslink services will increase to 24 trains an hour, connecting areas north and south of London with destinations through the capital.
And trains on routes serving London Bridge and Victoria will also be lengthened to 10 carriages, greatly increasing the number of passengers able to travel to and from destinations across south London.
Transport for London is currently leading a study to investigate options to make up for the withdrawal of the South London Line.
The mayor said: "One of the greatest parts of my job is being able to give the go-ahead to projects like the upgrade and extension of the East London Line, which will bring 125,000 jobs within 60 minutes of many communities in south London.
"However, the Department for Transport has made clear that in funding this project, they will not also fund a proposed Victoria to Bellingham service."
The upgrade will see the completion of the East London Line extension, with four trains per hour directly connecting Clapham Junction, the City and Docklands.