Passengers will not be able to travel from East Croydon to London Bridge for nine days next month due to Network Rail plans to completely redevelop London Bridge station.
With East Croydon serving up to 20 million passengers a year, it will cause huge delays for those travelling on the affected dates, August 23 to 31.
For those nine days, two of the three train operators which serve London Bridge station will be unable to call there due to the renovations.
Passengers are advised to check travel arrangements as they will be subject to change while the works are carried out.
East Croydon station manager Stephen Norris said: “We are expecting more passengers to be interchanging at East Croydon and my team are ready to assist with helping them.”
And Network Rail spokeswoman Nicky Hughes said: “London Bridge is one of the country’s busiest stations and we’re rebuilding it piece by piece to transform north-south travel through London while keeping it open for passengers.
"This is a huge challenge.”
First Capital Connect and Southern services south of Blackfriars will be very busy during this time.
Stations like East Croydon and Gatwick are expected to be busier than usual and passengers might not get on the first train.
The southern end of the Northern Line as well as District Line and Circle Line are also expected to be far busier than usual.
The London Overground will also be far busier than normal with no services to or from New Cross from August 26 to 29.
These services will be diverted to Crystal Palace to double the number of trains serving stations between Sydenham and Brockley.
There will be a bus replacement service running every 15 minutes between New Cross and Canada Water along with some additional bus routes to serve the very busy stations.
Passengers are being advised to go to ThameslinkProgramme.co.uk or follow @TLProgramme on Twitter for more information on the service as more changes are planned for December 2014 and between January 2015 and 2018.