Network Rail is reporting that signalling problems are causing 30 minute delays to train services between Stratford and London Liverpool Street.
There are also buses replacing trains on the line between Manningtree and Harwich.
Abellio, who run the Greater Anglia rail line, has been named Train Operator of the Year at the annual national Rail Business Awards.
Greater Anglia train operator Abellio says it's made real steps in customer service and punctuality in its first year in charge.
Greater Anglia have apologised for the delays that have disrupted services today