Buses are replacing trains between London Victoria and Gatwick Airport due to a landslip near Dorking and major improvement works.
Southern is operating a service between London Victoria and East Grinstead with onward bus connections to Gatwick Airport.
The improvement work is due to be completed in time for the start of service on Thursday 2 January, but customers are advised to check www.southernrailway.com before travelling.
But Southern warned that recent adverse weather may hamper some key elements of these works preventing the opening of the line, so advised travellers to check before they travel.
Meanwhile, Gatwick Express services are not running until 2 January due to planned improvement works.
