A safety inspection of the track between London Paddington and Heathrow Airport means fewer trains are able to run on some lines.
As a result, trains may be cancelled, delayed by up to 20 minutes or revised.
This is expected until the end of the day.
Effect on service:
Elizabeth line
Train services will not call at Heathrow Terminal 5 in either direction.
Heathrow Express
A reduced half hourly service will run between London Paddington and Heathrow Terminal 5.
Check before you travel:
You can check your journey using the National Rail Enquiries real-time Journey Planner
Compensation:
You may be entitled to compensation if you experience a delay in completing your journey today. Please keep your train ticket and make a note of your journey, as both will be required to support any claim.