There will be major disruption on the rail network while emergency repairs are made to a viaduct which suffered structural damage.
The urgent repairs are taking place on the Plessey Viaduct, affecting services between Newcastle and Morpeth, in Northumberland.
It means a reduced service is running between the stations, as only one out of four lines is open.
National Rail has now said there will be disruption on the route until at least the end of Friday, 3 November.
Services may be cancelled, or may not call at Morpeth in the southbound direction.
The five-arch viaduct was constructed in the late 1840s by Robert Stephenson and is Grade II-listed.
Network Rail said the parapet had moved, displacing about 30 tonnes of masonry and concrete.
Due to the site location, design of the viaduct, and the heavy machinery needed, moving the parapet back to its original location is not viable.
Network Rail Structural Engineers and external specialists are working on different options to repair the structure.
The structure of the viaduct has not been affected, a Network Rail spokesperson said. They added: "Train services are still running on one line of the viaduct. However, this does mean a reduced service is in place, as well as some bus replacement services, so passengers are urged to check before travelling via National Rail Enquiries or with their train operator."
Paul Rutter, route director for Network Rail’s East Coast route, said: “Our teams are working hard to repair damage to Plessey Viaduct. While we want to minimise disruption to travellers, the safety of passengers is our top priority.
“We are sorry for the inconvenience this will cause to journeys and we want to thank passengers for their patience and understanding while we carry out this vital work.”
A spokesperson on behalf of train operators said: “We want to thank our passengers for their patience as Network Rail carries out essential work to repair Plessey Viaduct. There is a reduced service in place, and some services are not stopping at Morpeth, Cramlington, and Manors stations.
“We are advising passengers to check before they travel with National Rail Enquiries or via their train operator.”
CrossCountry between Penzance / Plymouth / Bristol Temple Meads / Birmingham New Street and Edinburgh, and between Plymouth and Glasgow Central / Dundee
LNER between London Kings Cross and Edinburgh / Glasgow Central / Aberdeen / Inverness
Northern between Metrocentre / Newcastle and Morpeth
TransPennine Express between York / Newcastle and Edinburgh
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