The first phase of work to enhance services at London Bridge railway station is set to get underway this month.
Network Rail has confirmed that three platforms will be taken out of use until spring 2014 and that platforms eight to 16 will be temporarily closed over the late May bank holiday to enable the project to get started.
The company said the changes are vital in order to create more capacity to, from and through the station. At the moment there are six through and nine terminating platforms at the station, but this will be changed to nine through and six terminating platforms by 2018.
This means rail companies can increase the capacity of their services and trains will no longer have to wait outside the station until a platform is free.
Network Rail's managing director of network operations Robin Gisby said: "Once complete London Bridge will unlock the full benefits of the Thameslink programme and increase capacity through central London."
A number of prominent London-based stations have been upgraded in recent months, including King's Cross, which received a huge new western concourse.