The Gatwick Express will not run from Brighton this week as a result of the closure of London Bridge station.
Commuters have been warned that all services across the network are likely to be busy.
No Southern and First Capital Connect services will call at the station until Monday 1 September.
Many commuters were not aware that Gatwick Express trains would not be calling at Brighton Station this week.
A spokesman for Southern which runs the service said: “It is accurate to say that the Gatwick Express extensions are not running this week. This is because we have had to make changes across our network to accommodate not running into London Bridge.
“We have conducted an extensive communications campaign – based on what is running, rather than what isn’t.
“This week, passengers wanting Gatwick Airport from Brighton have five trains per hour during the morning peak – one Southern service and four First Capital Connect services. Southern tickets are being accepted on First Capital Connect services and vice-versa.
“Passengers wanting London Victoria from Brighton have three Southern services per hour all day. Two of them (leaving at 19 and 49 minutes past the hour) call at East Croydon and Clapham Junction and the other one (leaving at 24 minutes past the hour) calls at Hassocks, Burgess Hill, Gatwick Airport and East Croydon.”
