Greater Anglia has warned passengers not to travel on the affected routes and apologised for the inconvenience. A spokesman for Greater Anglia said: "We apologise for the inconvenience and thank you for your patience and understanding. "When lines do re-open, we are expecting trains to be disrupted, as trains were not able to finish in their normal depots." Advance purchase ticket holders are permitted to use earlier or later trains if their booked service was cancelled. Greater Anglia and Network Rail apologise for any delays.