Passengers are facing widespread disruption on the southern rail network.
A radio communication fault affecting the southern rail network is causing delays and cancellations across the entire southern network, with services expected to be disrupted until 2.30pm.
The issue affects lines operated by Gatwick Express, Great Northern, Southern and Thameslink.
A Network Rail spokesperson said: “There is a problem with the railway’s radio system.
“This links train drivers with the signallers who control the rail traffic on each route.”
“A fault with the radio system between the driver and the signaller means that trains have to run at reduced speed on all lines.”
Journeys began experiencing delays from 12.48pm, with trains potentially cancelled, postponed by up to 20 minutes or subject to last-minute changes.
Rail operators have advised passengers to allow extra time and to check station information screens and announcements before boarding.
Travellers in the London area are encouraged to consider alternative routes using Transport for London’s journey planner.
Work is underway between the operators and Network Rail to resolve the technical fault as quickly as possible.
The radio system is essential for communication between train drivers and signallers, who manage the safe movement of rail traffic.
Passengers delayed by the disruption may be eligible for compensation and are advised to keep their tickets and note the details of their journey.
Live departure boards and real-time journey planning tools are available on the Southern and National Rail websites.
Customers who experience delays are encouraged to submit a compensation claim through the National Rail website.
