Rail staff on part of the Greater Anglia network are being balloted on strike action after the RMT union accused the operator of "ripping up" procedures.
Members of the Rail Maritime and Transport union on Greater Anglia's West Anglia route will vote in the next few weeks on whether to launch a campaign of industrial action.
The union claims that changes being planned by the company will lead to the axing of station cleaners' jobs.
Some Greater Anglia services between Romford, Upminster and Liverpool Street are being cancelled and others delayed due to an earlier derailment at Ilford.
Tickets for train services are being accepted on local bus routes. Greater Anglia say they have no estimate of when normal service will resume.
Greater Anglia train services between Broxbourne and Cheshunt have been disrupted because of emergency engineering works.Tickets are being accepted on London Underground, First Capital Connect and London bus services.
A signalling problem between Wickford and Southminster has disrupted Greater Anglia services. A supplementary bus service is running on the whole Southminster branch with journey times extended by up to 30 minutes. There is currently no estimate for when a normal service will resume.
There is disruption on Greater Anglia bservices etween Liverpool Street and Cambridge, and Stratford and Bishops Stortford due to person hit by a train.
Services may be cancelled or stopped while emergency services are on site. It Also affecting Stansted Express.
A Greater Anglia spokesperson said:
Greater Anglia and South West Trains have been branded the worst value for money by passengers.
A survey by the independent watchdog Passenger Focus found that travellers on their routes were the least satisfied with the price of their tickets. Only 37% of passengers considered their tickets value for money, compared with as many as 73% for other operators.
But, despite its poor rating, Greater Anglia's score was an improvement on last year - when it managed only 33%.
Nationally, the proportion of rail passengers satisfied with the price of their tickets has risen by one percentage point to 47% since autumn 2011.
Click here to read the full report.
Delays of up to one hour on Greater Anglia between Liverpool Street and Norwich, and between Liverpool Street and Ipswich due to earlier broken down train at Manningtree.Tickets being accepted on First Capital Connect, Underground services.
Greater Anglia services have been suspended between Romford and Upminster because the emergency services are dealing with an incident at Romford. Tickets are being accepted on local busroutes.