Disruption on the railways between Hastings and Tunbridge Wells is expected until 4pm, according to Southeastern.
Trains have been cancelled, delayed or revised between the two stations since 6.30am due to a fault with the signalling system.
Southeastern said disruption is expected until 4pm today (Wednesday, February 13).
In a statement, Southeastern said: “The signal problem has unfortunately returned, as such all trains are suspended on the route. Trains will only run as far as Tunbridge Wells to and from London.
“You can use the following at no extra cost to help complete your journey.
“Southern Services between Hastings and Ashford International and Hastings and London via Lewes, also you can use Southern Services between Uckfield and London Bridge.
“High Speed services between Ashford international and St Pancras.”
Southeastern has advised passengers to allow extra time to reach their journey and check on line journey planners for latest details.
Southeastern added: “We’ll update you here with the latest information direct from our control room.”