There are massive delays on the trains in and out of London with disruption expected until this afternoon.
Trains from St Albans into London and back out again are severely affected by a problem between Blackfriars and London St Pancras.
Travellers are advised to check their journeys and plan for delays as Thameslink are reporting that they expect this to last until 3pm.
Affected services include:
Cambridge and London - Some services will run to and from London Kings Cross
Peterborough and London - Some services will run to and from Kings Cross
Brighton and London Bridge - Passengers may wish to travel to and from London Victoria using Southern services.
Bedford and London St Pancras International.
For more information visit www.nationalrail.co.uk/service_disruptions/232319.aspx
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