THERE are cancellations and delays of up to an hour on the Brighton Mainline after a fault with the signalling system.

Southern Rail warned passengers to expect disruption on the line until 8pm.

A spokesman said: "A fault with the signalling system between Gatwick Airport and Haywards Heath is causing disruption to journeys between these stations.

"Train services running through these stations may be cancelled or delayed by up to 60 minutes.

"Please allow extra time for your journey today."

The fault happened at about 12.40pm.

It is affecting routes between London Victoria and Brighton which have been "reduced to regulate the flow of trains in the affected area and prevent congestion and heavy delays from building up".

Passengers using the Thameslink services between London Bridge and Brighton, and London St Pancras and Brighton, have also been warned to expect delays of up to 30 minutes.

Southern, Thameslink and Gatwick Express services are all running "heavily reduced services" to try to ease disruption in the area.

The company's website said customers would be able to use their tickets on alternative bus and rail services.

These included Southern and Thameslink services, Metrobus services between Gatwick, Haywards Heath and Horsham on routes 271, 272 and 273, Gatwick Express services between London Victoria and Gatwick and London Underground services on reasonable routes.

It also said Brighton and Hove buses on the 2 (Brighton, Hove, Portslade, Shoreham by Sea, Southwick), 6 (Portslade, Hove, Brighton), 7 (Brighton, Hove)

21, 21A, 21E (Brighton, Hove), 46 (Southwick, Portslade, Brighton), 49 (Portslade, Brighton) and 60 (Brighton, Shoreham, Southwick) could be used.

A Southern Rail spokesman said: "The fault has been confirmed as a 'Multiple Track Circuit Failure'.

"This means the signalling system is unable to automatically verify if the next section of track past the affected signal is clear.

"The rail network is designed so that if a signal stops working, trains will stop before they reach it.

"Whilst this issue is ongoing, train crew will stop at the affected signal and contact the signalling centre to confirm their location, which at this point the signaller will verbally authorize the driver to continue towards the next signal.

"This process adds time to every trains journey, which means services will experience delays.

"Network Rail Operatives are working hard to rectify the issues with the signalling system, they are on site carrying out tests and investigations.

"During this time a special working has been introduced in the affected area, services will be given authority by the signaller to pass the signal, but only one train can be guided at a time."