Urgent repairs to the track between Harrow-on-the-Hill and Aylesbury means trains running between these stations may be delayed by up to 20 minutes or cancelled.
Disruption is expected until 15:00.
Check before you travel:
You can check your journey using the National Rail Enquiries real-time Journey Planner
Twitter:
If you would like to follow this incident on Twitter, please use #Aylesbury
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.