Restoration efforts on the railway corridor where a passenger train came off the rails are approaching their final stages.

The route connecting Haywards Heath with Lewes has been non-operational since mid-August, when a Southern-operated service travelling from London Victoria toward Eastbourne left the tracks on its arrival at Lewes station.

Emergency services transported 20 individuals to medical facilities, with two casualties requiring admission to specialist major trauma units due to the seriousness of their injuries.

According to a preliminary assessment released by the Rail Accident Investigation Branch, footage captured from other rail services that had traversed the section earlier in the day revealed what was described as an irregularity in the track geometry immediately preceding the location where the train derailed.

Investigators additionally noted indicators of prior maintenance work having been performed on the track in that vicinity.

Since the occurrence, technical teams have been executing a recovery plan encompassing the removal of the three carriages that left the rails, rehabilitation of the embankment, and preparation for the reinstatement of signalling infrastructure.

According to updates from Network Rail, recent operations have centred on earthwork stabilisation ahead of track replacement procedures scheduled to commence on August 27.

The organisation reported that progress on returning the railway to service continues to advance satisfactorily.

The line is anticipated to resume operations on September 1, with engineering staff set to conduct comprehensive testing and safety verification of all infrastructure prior to the reopening.

Throughout the closure period, rail users seeking connections to Eastbourne and Lewes have been directed to utilise alternative routing through Brighton, while replacement bus services are operating between Haywards Heath and surrounding stations.