MP Nick Herbert has made a renewed call for Network Rail to install an alternative route for passengers on the Brighton mainline after widespread flooding caused travel chaos this week.

The plea comes as bosses at the rail company confirmed they would consider the MP's proposal for a diversion onto the Arun Valley line whenever the Brighton mainline is temporarily closed.

Thousands of passengers were left delayed for hours at Brighton station on Monday after heavy rain caused groundwater flooding at Patcham, bringing the mainline to a near standstill in some areas.

The Conservative MP for Arundel and South Downs said the “Arundel Chord” would provide a direct link between Horsham and Worthing on the southbound Arun Valley line if the Brighton mainline was closed.

He said: “Adding a tiny section of railway below Arundel to enable trains from Brighton or Worthing to turn north onto the Arun Valley line would enable services to run from Brighton to London in the event of problems or maintenance on the overstretched Brighton line.

“Monday's flooding, which meant that thousands of commuters were unable to go to work, was a timely reminder of why the Arundel Chord could prove a good investment.”

Network Rail had originally dismissed the idea of the new route claiming that while it was used as a diversion it would add at least 50 minutes to travel times in normal circumstances and no-one would want to run services on it.

In a letter to the MP last year Tim Robinson, Network Rail's managing director on the Sussex route, added that the diversion would mean trains rejoining the mainline would not be able to call at Crawley, Gatwick and Croydon, which he claims are all important stops on the mainline route.

But Network Rail spokesman Chris Denham said the company is now including the line in its new route study, which is due out later this year, to consider if it could be used at times of disruption.

Adam Love, Sussex route public affairs manager at Network rail said it was too early to identify potential stations or stopping patterns on the potential line.