Train services between Norwich and London Liverpool Street will be severely disrupted this week after damage to a railway embankment.
One of the two lines is blocked after the damage at Ingatestone, Essex.
Network Rail engineers are on scene to clear the debris and repair the damage and restore the train services.
But the repair works are not expected to be completed until the end of this week, according to Greater Anglia.
A statement on the Greater Anglia website said: "As a result, train services running between Liverpool Street, Colchester, Clacton-On-Sea, Ipswich and Norwich will be significantly reduced due to only one line available for train traffic between Shenfield and Chelmsford.
"As there is engineering work taking place this weekend and no trains will be running between Liverpool Street and Witham, disruption is expected until 4am on Monday, February 1."
Customers are advised to expect delays, alterations and cancellations.
A Network Rail spokesperson said: "Following the embankment repair works over the weekend and earlier today at Ingatestone, we have found that there are further issues with the stability of the embankment. Unfortunately we will therefore need to keep the affected line closed for rest of the week, including this weekend, whilst we implement remedial action.
"We are continuing to work closely with Greater Anglia to reduce the impact on services, as far as possible, while we continue with the repair work.
"Passengers are advised to check Greater Anglia’s website or app for the latest travel information. Passengers should also follow government advice and only travel for work if essential or for other legally permitted reasons. We will provide a further update later in the week about when the line can fully reopen. We are sorry for the ongoing disruption caused to passengers by these necessary emergency repairs."
Due to the repairs there will be one train an hour in each direction leaving London Liverpool Street at half past the hour and Norwich on the hour.
That service will stop at Stratford, Shenfield, Ingatestone, Chelmsford, Hatfield Peverel, Witham, Kelvedon, Marks Tey, Colchester, Manningtree, Ipswich, Stowmarket, Diss and Norwich in both directions.
Greater Anglia and Network Rail have apologised to passengers if their journeys have been affected.
For updates visit www.journeycheck.com/greateranglia
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