Rail passengers have been warned of severe disruption after train services at Paddington station were suspended.
Services had initially been expected to be disrupted until 6pm. This was then changed to 8pm, before the rail company announced that services would be affected for the rest of the day.
The problem has also delayed trains travelling from Reading and Heathrow Airport.
Services run by GWR, Heathrow Express and the Elizabeth line are disrupted.
Passengers with tickets on cancelled or delayed services can use them on South Western Railway, Chiltern, Elizabeth Line or London Underground services.
In a tweet, GWR said: “Due to damage to the overhead electric wires between London Paddington and Slough some lines towards London Paddington are blocked. Train services running to and from these stations may be cancelled, delayed by up to 60 minutes or revised.
“Disruption is expected until 20:00. Ticket acceptance is in place with SWR, Chiltern, TfL on the Elizabeth Line and the London Underground via any reasonable route until further notice.”
National Rail Enquiries is showing that all services to and from Paddington are “delayed” or “cancelled”.
This is the second time in a week that trains have been suspended from Paddington, with services on Monday affected by the same problem.