Last month Assembly Members heard that TfL was hoping to secure control of, or input into, the franchises, providing commuters with a London Overground level of service.
The Overground was built out of the failing Silverlink franchise and is now one of the UK’s most reliable and highest performing rail services.
Passengers have benefited from investment in new trains, refurbished stations and visible staffing.
Responding to the Government’s consultation on rail decentralisation, AMs on the Assembly’s Transport Committee said devolving the routes to TfL would result in better services, less bureaucracy and end passenger confusion around fares.
AMs say that while national Government should continue to set standards for outer-suburban and long-distance services, it backs TfL’s calls to set fares and service standards on inner-suburban routes.
TfL also wants all inner-suburban routes to carry London Overground branding.
Committee chair Caroline Pidgeon said: “At the moment ten different operating companies run various parts of London’s suburban rail network. The result is a confusing mix of provision, quality and fares.
“We believe Transport for London’s oversight would lead to more consistency and better services for passengers.
“Their success with the capital’s orbital rail network makes an excellent case for devolving control of inner-suburban franchises to the Mayor and Transport for London – starting with Southeastern and West Anglia.”