The work will affect trains on Sunday (March 30) only.
Services will resume as normal on Saturday (March 29).
We have listed all the details for you to plan your journey this weekend.
Sunday (March 30):
Engineering work is taking place between Tulse Hill and Tooting or Mitcham Junction, closing all lines.
Replacement buses will run between Tulse Hill and Sutton.
Trains between London Bridge and East Croydon via Peckham Rye will be diverted via Crystal Palace and Norwood Junction.
Trains between London Victoria and Epsom or Dorking will run to an amended timetable and will be diverted with extended journey times.
Journey times will be increased when using replacement buses.
Engineering work is also taking place between London Victoria and Clapham Junction, closing some lines.
All day on Sunday, a reduced train service will run between London Victoria and Clapham Junction or East Croydon.
Trains to London Victoria will not call at Battersea Park.
Some services will be diverted to run between London Bridge and Three Bridges. Services between London Victoria and Reigate will run between Redhill and Reigate only.
Passengers should use alternative Southern or Thameslink services between London stations and Redhill.
