Over-running engineering works are causing disruption near London Bridge.
Because of this, there are delays of up to 80 minutes to journeys between New cross and London Bridge.
These delays will continue until further notice.Trains between Dartford and London Bridge via Greenwich may be diverted via Lewisham.
First Capital Connect services are currently unable to call at London Bridge.
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The action comes on top of an emergency timetable which has seen hundreds of trains a day being axed.