There is a nationwide fault with the train's onboard communication system. As a result, services across the Gatwick Express, Great Northern, Southern and Thameslink network may be cancelled, delayed by up to 15 minutes or revised.

We expect this to continue until 07:30

Customer advice:

Services across the Southern, Thameslink, Great Northern and Gatwick Express network are expecte to be disrupted this morning. Services may experience some delays of around10-15 minutes, and may be subject to short notice alterations and cancellations as a result.

For most journeys, you can travel using your normal route today. However, if your planned train is affected then you may need to take an earlier or later train instead, change trains en route, or use an alternative route.

Tickets will be accepted for no extra cost on the following:

• Southern, Thameslink and Great Northern services via any reasonable route
• London Underground on any reasonable route between London Terminals

Please note that there is no ticket acceptance on Gatwick Express services at this time.

Planning your journey:

Live departure boards can be found here.

You can view a live map of the network here.

You can also see an alternative route guide here.

If you're travelling in the London area, you can plan journeys on alternative routes by using the TfL Journey Planner here.

You can also use GTR's app to find up-to-date information.

Can you tell me more about the incident?

A fault with the radio system between the driver and the signaller means that trains are unable to run to / from Moorgate this morning and services across the network may be delayed. Investigations are ongoing as to why this has occurred and efforts underway to get it rectified as soon as possible.

We'll provide further updates on this as soon as we get them.

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.