THE pressure is on Network Rail to expand East Croydon Station by providing two new lines and platforms.
The council and Gavin Barwell MP are pushing for work to start on the project to coincide with the opening of the revamped Whitgift Centre in 2018.
The £1 billion Westfield/Hammerson development is expected to significantly increase passengers coming into East Croydon.
The concerns are that existing congestion at the station will become worse if nothing has been done about the track and platform expansions in time for the opening.
Croydon Central MP Mr Barwell, who was planning a meeting with Network Rail this week, said: "It is essential that we get this work done as soon as possible."
At present no money has been scheduled for the scheme in the 2014-2019 funding tranche, with much of that budget going towards improvements in the Redhill area.
In a statement issued this week, Network Rail said tackling congestion points at East Croydon and Windmill Junction, on the northern side of the station, were being looked at as the next possible project to follow the Redhill scheme.
The statement read: "The ideal time to get cracking on those is the early part of the next control period, from 2019-2024, as the area is due to have its signalling renewed then."
Bringing the two sets of work together is considered by Network Rail as the most cost-effective way of bringing about the improvements.
All the works are designed to reduce pressure on pinch points on the London to Brighton line, which Network Rail said "limit the number of trains we can run and make it harder to recover from delays when they do occur".
The statement continued: "We are working with MP Gavin Barwell and other interested parties to build the case for doing the work, and the funding to match.
"Our Route Utilisation Strategy will be published next autumn, which will have a more detailed breakdown of the work that is needed to keep this stretch of railway running in the next 30 years."
Mr Barwell said he would be lobbying for Government funding to fast-track the scheme, adding: "I want to get ministers down here to look at the situation."