A derailed train which left thousands of passengers delayed has been blamed on “driver error”.

Chaos was caused on the rail network after the driver went through a red light at around 2pm on Wednesday. The blunder caused disruption across the network until around 3pm yesterday.

The out-of-service train was leaving the Lovers Walk train depot outside Brighton station when it derailed. All services between Brighton and Hove, on the Brighton Mainline and Brighton and Lewes were affected.

Thousands of passengers were forced to take replacement bus services on the hottest day of the year.

The carriage was back on the tracks by midday yesterday and taken back to the depot.

Cables supplying power to the track were also damaged, but repaired during the removal effort.

Southern Rail said: “The investigation into the derailment is still ongoing. However, it appears that the cause was driver error.

“The empty train was approaching the main line into Brighton station as it was leaving the depot. The train passed a red signal and the infrastructure did what it was designed to do and stopped the train.”

Southern Rail has been criticised for not acting quickly enough to remove the derailed train and resume normal services – despite working through the night on Wednesday evening and Thursday morning to move the train.

An image showing dozens of Network Rail staff apparently pushing the train back to its depot emerged on social media yesterday.

Passengers responded in fury and jest. Tom Phillips wrote: “Surely there is a better way of moving the derailed train outside @brightonstation than just... pushing it by hand.” Helen Day said: “I know how that train feels. There are moments when I have felt most derailed, waiting out- side Brighton station.”

A Southern Rail spokesman told The Argus: “The reason it took longer than anticipated is that the wheels of the derailed bogey were embedded quite deeply into the ballast - the stones you see on the track bed - and it wasn’t until the early hours of the morning that it became apparent that it was going to take longer than antic- ipated to re-rail the carriage.

“While it was being done, power into and out of the station had to remain off for the safety of the lifting crew which is why we didn’t have trains running between Brighton and Preston Park at the time.”