No Southeastern trains will run to or from London Victoria from Saturday, December 27 to Wednesday, December 31, with all services diverted to alternative London terminals.
Southeastern has announced the disruption is caused by major engineering work closing all lines it operates into Victoria station.
The closure will affect several routes across south London and Kent, with replacement bus services and amended train schedules in place.
During the closure period, all Southeastern routes normally running to London Victoria will instead be diverted to London Cannon Street or London Charing Cross.
There will be no Southeastern services between London and Beckenham Junction via Herne Hill.
Stations between Herne Hill and Beckenham Junction, including West Dulwich, Sydenham Hill, Penge East, and Kent House, will be closed throughout the works.
These stations will only be served by accessible replacement buses running between Denmark Hill and Beckenham Junction.
Additional changes will affect lines serving Kent.
Trains between London Victoria and Ramsgate via Chatham will operate to and from London Cannon Street, running non-stop between London Bridge and Rochester.
Services to Dover Priory via Chatham will also start from Cannon Street.
Stopping services between Victoria and Gillingham will begin at Cannon Street and skip stops between London Bridge and Bromley South.
The Maidstone East line will also see changes.
Trains to Ashford International will run non-stop between London Bridge and St Mary Cray.
Extra trains will run between London Cannon Street and Swanley, calling at London Bridge, Bromley South, and St Mary Cray.
Brixton station will be closed throughout the engineering works, though London Underground services will remain available.
Additional services will instead operate between London Charing Cross and Dartford via Bexleyheath.
Sunday, December 28 will see similar route changes, including those on the Sole Street, Maidstone East, and Bromley South lines.
On this date, Bromley South services between Victoria and Orpington will be diverted to start and end at London Charing Cross, running via New Beckenham and calling at Waterloo East, London Bridge, Ladywell, Catford Bridge, and Lower Sydenham.
Hayes line services not running via Lewisham will be diverted at New Beckenham to terminate at Orpington.
These diverted trains will call at Beckenham Junction, Shortlands, Bromley South, and either Bickley or Petts Wood.
Southeastern has advised passengers to check their journey before travelling and allow extra time as journeys will take longer during the engineering works.
Passengers are also encouraged to use the National Rail Enquiries journey planner to find the best route during the disruption.
London Underground services from Brixton station will remain in operation, providing an alternative for some commuters.
Replacement bus services will be accessible for passengers with mobility needs, ensuring all travellers can complete their journeys.
