The changes are due to engineering work and will affect trains on Saturday and Sunday (August 16 and August 17).
We have outlined and simplified the details so you can plan your journey this week.
Sunday (August 17):
Engineering work is taking place between Clapham Junction and Watford Junction, closing all lines.
No Southern trains will run between Clapham Junction and Watford Junction.
Passengers should use London Northwestern Railway trains between London Euston and Watford Junction, Southern trains between Clapham Junction and London Victoria, and on London Underground between Victoria and Euston.
Saturday and Sunday (August 16 and 17):
Engineering work is taking place in the Barnham and Worthing area, closing all lines.
Saturday:
The 10.35pm train from London Victoria to Chichester train will terminate a Barnham.
A replacement bus will run from Barnham to Chichester.
The 11.16pm train from London Victoria to Chichester train will terminate at Worthing.
A replacement bus will run from Worthing to Chichester.
Sunday:
Before approximately 7.45am on Sunday, buses will replace trains between Littlehampton and Barnham, and Angmering and Barnham via Littlehampton
Trains will run to an amended timetable between Brighton and Angmering and between Barnham, Bognor Regis, Portsmouth Harbour, and Southampton Central.
