A fault with the signalling system between Stevenage and London means trains have to run at reduced speed on some northbound lines. Train services running between these stations may be delayed.

Disruption is expected until 09:00.

Additional information:

Two separate signalling problems have occurred in the Potters Bar and Stevenage areas. Network Rail response staff are aware and dealing with the issues.

The same line is affected at both locations - this is the line usually used by northbound express services which run towards Peterborough and Cambridge, and also towards the North of England.

Advice for Southern and Thameslink customers:

Minor delays are currently affecting some northbound trains through Potters Bar, and also through Stevenage.

You can use your normal route for travel, but please be aware of these delays.

These problems mainly affect trains between:

- London Kings Cross and stations to Royston, Cambridge, Ely and Kings Lynn (Great Northern)

- Brighton and Royston / Cambridge (Thameslink)

- Horsham / Gatwick Airport and Peterborough (Thameslink)

If you are waiting at stations between London and Peterborough or between London and Cambridge, you may find some trains are running in a different order compared to the timetable, or may depart from a different platform at your station, compared to the one which is usually used.

Please listen carefully to all announcements and check the screens at the station before you board your train.

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 #Stevenage

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.

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