A 1000 m tunnel is set to receive a £15 m upgrade following investment from National Rail.

From January 18th until February 10th next year, the line between Tiverton and Taunton will be closed as work starts on upgrading Whiteball tunnel.

This will involve repairing the old structure so it does not deteriorate, while expanding the drainage system to reduce the threat posed by extreme weather. The Tiverton end has already been marked as a flood risk.

Three miles of track will also be renewed, with new crossings and switches. As a result, trains will able to travel through at a higher speed of 80 miles per hour.

Director of asset management on the Western route for Network Rail Mike Gallop said the organisation will be "carrying out essential improvement works on a vital rail link and on one of the more popular freight and commuter routes in the south west of England".

During this time, however, the tunnel will be closed. First Great Western will be offering alternative services but, in some cases, passengers may have to plan journeys as much as 65 minutes earlier than normal.