A fault with the signalling system between Didcot Parkway and Swindon means that trains have to run at reduced speed on the line towards Swindon.
As a result, trains runnning between these stations may be delayed by up to 30 minutes.
Disruption is expected until 12:45.
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.