Network Rail has submitted a planning application for works to create five new platforms for domestic services at London Waterloo station.
The infrastructure operator intends to bring platforms 20-24 of the terminus back into use.
The five platforms – currently part of the disused Waterloo International – would help the busy station cope with an anticipated boom in demand.
If the work gets approved, three bridges will need to be strengthened, and the layout of track and platforms altered.
It would represent the first major changes to Waterloo station since the 1930s.
Work could start as soon as October and is scheduled to be completed by the end of next year.
Network Rail route infrastructure director John Halsall said: “The project to improve the railway and strengthen the bridges on the approach to Waterloo is an absolutely vital part of our plans to improve capacity at Britain’s busiest station.
“The submission of the planning application to carry out this work is an important step forward and, if approved, we expect to start work before the end of the year.”