The line between Effingham Junction and Guildford has closed in order to allow Network Rail engineers to complete emergency works.
Ground movement has been detected at an embankment in the Clandon area.
Services between Waterloo and Guildford via Cobham & Stoke D’Abernon, and via Epsom, will be disrupted until Tuesday.
SWR will operate limited services between Waterloo and Effingham Junction, via Cobham & Stoke D’Abernon, and via Epsom.
Some suburban services between Waterloo and Guildford will also be diverted via Woking.