Railway engineers have been carrying out trackside repairs to prevent a large bank slipping on to the main Brighton Line.
There was evidence a large section of bank near Earlswood, Surrey, at Stokes Nest Junction, was in danger of slipping on to the track, taking trees and shrubs with it.
The danger was first spotted in the early hours of Sunday and engineers have been mounting a stabilisation programme, which involves building a new retaining wall close to the track.
It is hoped the work would be completed early today.
Trains have been diverted via Redhill while the emergency work takes place, causing delays of up to half-an-hour between London and the Sussex Coast.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article