City commuters are facing delays into London Liverpool Street this morning, but not because of signal failures, as is usually the case.
Slippery rails are being blamed for the disruption on TfL Rail services between Shenfield and Liverpool Street.
As a result of the conditions, trains my be cancelled or delayed, National Rail warned.
Disruption is expected to continue until 10am.
Tickets will be accepted on London Underground, London Overground, Greater Anglia, C2C and London bus services.
Meanwhile, National Rail said due to failure of the electricity supply earlier today between Moorgate and Finsbury Park, train services running to and from these stations may be delayed by up to 20 minutes. Disruption is expected until 10:30am.