One of the two lines will remain closed so that engineers can assess the scale of the damage and check that there is no risk of further landslips, following which a repair plan will be produced.
The landslip has affected the line from Coventry to Rugby, but train services can still use the other line.
However, a reduced timetable will be in place and passengers should check their journey in advance at www.nationalrail.co.uk.
A rail replacement bus service will run every 30 minutes between Coventry and Northampton.
The landslip may also affect Avanti West Coast services, which may be delayed or cancelled.
Tickets will be accepted on the following alternative routes:
- London Northwestern Railway trains on any reasonable routes;
- CrossCountry Trains between Coventry and Stafford;
- Chiltern Trains between Birmingham Moor Street and London Marylebone;
- CrossCountry Trains between Birmingham New Street and Reading and Great Western Railway trains between Reading and London Paddington.
Phil Barnes, operations director for Network Rail, said: “Network Rail engineers are assessing the damage caused by a landslip between Coventry and Rugby and are working on a plan to safely reopen the affected track as soon as possible.
“With one of the two tracks in this area closed to trains, a reduced service is running through the area and we apologise for the disruption to journeys.”
“We advise passengers to check www.nationalrail.co.uk or with their train operator for the latest travel advice.”
Jonny Wiseman, LNR customer experience director, said: “This landslip has resulted in a significant amount of earth movement next to the railway, meaning it is not safe to run trains through the area until Network Rail has completed emergency earthworks.
“Customers planning to travel between Birmingham New Street and London Euston on Monday should check their journeys before setting out, expect extended journey times and should consider using alternative routes if possible.
“Our website and social media pages are being kept up to date with the latest travel advice and we urge passengers using this area to plan ahead and check before travelling until the railway is safe to reopen.”
Dave Whitehouse, safety and security director at Avanti West Coast, said: “The landslip between Rugby and Coventry means our services to London Euston are unable to operate as normal while Network Rail complete the emergency repairs.
“We are working with Network Rail and other train operators to ensure our customers are able to still travel to and from London while this work takes place over the next days.
“The latest travel information will be on our website as well as social media. The main advice to our customers is to plan ahead before you leave, check before your travel and expect longer journey times. We would like to thank our customers for their patience at this time.