A large landslip that left one of the tracks of the main London to Basingstoke line hanging in mid-air will affect train services on the Portsmouth to Waterloo line.
A knock-on of the ‘huge’ landslip on Sunday at Hook saw scores of rail users stranded at Petersfield rail station as services were left in disarray after the incident.
The slip, on an embankment near Hook station, has left only two tracks of the four-track railway passable by trains, with both tracks designed to be used by London-bound trains only.
South Western Railway customers are advised to check before they travel until advised otherwise, as there could be major changes to train services for some time.
Network Rail Wessex route director Mark Killick said: “This is a huge landslip and will have a massive effect on customers.
“I can only apologise for the scale of the disruption and please ask that customers check before they travel this week, not just on the affected section, but all the way up the line to London Waterloo, where many of the trains that would use this section of railway start and finish their journeys.
“We’re still assessing the damage and it’s difficult to put a detailed timescale in place, but we know it’s going to be at least a week.
“We will need to stabilise the embankment, essentially stopping it moving, and then rebuild the railway where it has slid away.
“We’ll keep everyone informed of our progress and I can only say thank you to everyone for their patience and apologise again for the disruption.
“Please look out for further updates from South Western Railway on the revised timetable, once this has been able to be confirmed.”
On Monday (January 16) Petersfield rail station ticket office advised passengers to check on services before making arrangements to use the line.
And at least two trains were cancelled due to the slip, and others were late.
The embankment is made of mixture of London Clay and other local soils, saturated after days of heavy rain and a very wet winter.
The slip happened when the soil gave way along a 44 metre section of 10m high embankment, sliding out from underneath the tracks, in what engineers call a “rotational failure”.
Network Rail and its suppliers are working on designs for the work needed to repair the railway, which will give a clearer idea of timescales.