National Rail confirmed trains between Reading and London Paddington may be cancelled or delayed by up to 30 minutes at around 7.20am today (August 5).
This is due to a points failure at West Drayton Station.
Lines have reopened although disruption is still expected until 12.30 today.
The problem is affecting two of the four lines between Reading and London Paddington.
National Rail are having to reduce the train service through the area to avoid congestion.
Local stopping services between London Paddington and Didcot Parkway, Newbury will only run between Reading and Didcot Parkway, Newbury.
Tickets can be used at no extra cost on Elizabeth line services between Reading and London Paddington.
Routes affected
Elizabeth line between Abbey Wood and Maidenhead and Reading.
Great Western Railway between London Paddington and Bristol Temple Meads, Cheltenham Spa, Great Malvern, Frome, Oxford, Didcot Parkway, Weston-super-Mare, Worcester Shrub Hill, Cardiff Central and Hereford, Swansea, Plymouth and Penzance.
