Due to a points failure between Clapham Junction and London Waterloo, routes between the two major stations closed for several hours.
The lines have since reopened and the service has begun recovery, but trains running between these stations may still be cancelled or severely delayed by up to 60 minutes.
The delays are being caused by the displacement of train crew and stock. Disruption is expected until 4pm.
A statement on the National Rail website says: “There was a problem with multiple sets of points between London Waterloo and Clapham Junction.
“All lines have re-opened.
“Train service recovery is well under way, however due to train crew and train stock displacement, services are still expected to be delayed, revised or cancelled at short notice until further notice.”
Passengers are entitled to compensation if they experience a delay in completing their journey today.
Passengers should keep their train ticket and make a note of their journey, as both will be required to support any claim.
