A lack of maintenance work has been cited as the reason for the chaos on the trains this week.

Commuters continued to face travel misery at Farringdon station yesterday after a flood in a train tunnel despite rail operators suggesting a normal service should have resumed.

The huge leak from a 16-inch mains pipe swamped the tracks near the station last week, causing days of chaos for train users across the capital.

Thames Water fixed the leak, but were concerned as to why the standing water wasn't draining and so inspected Network Rail's system.

Thames Water director Bob Collington said: “The water in the tunnel cleared as soon as we cleaned out Network Rail’s surface drainage system last night.

“The pipe was full of silt and debris, and a grill which would have allowed the water to drain away was blocked solid. Basically, the water had nowhere to go.

“We believe this problem was first identified as far back as 2007, and the problems with water on the track have been caused by a lack of maintenance on their part.

“Our teams have done a fantastic job resolving this issue, and we will be presenting our findings to Network Rail as part of a full investigation into what has caused this terrible disruption to passengers.”

The meeting is in Derby on Tuesday.