Southern rail commuters are being advised to check before they travel, as strike action is once again affecting services.
Conductor members of the RMT union walked out at midnight amid continuing disputes over their role.
Services will be significantly affected on Monday, December 19 and Tuesday, December 20 whilst the conductors strike is carried out.
Southern have tweeted to advise passengers that there will be limited service, with an amended timetable in place:
There are no trains on some routes today, and after 6pm there will be no services running.
Last week there were no trains in operation on Tuesday, December 13, Wednesday, December 14 and Friday, December 16 due to strike action by The RMT and Aslef unions.
The driver's union Aslef staged a walk out over potential changes to their role.
Under new changes, Southern intends to make drivers responsible for monitoring the opening and closing of doors, which they believe would be unsafe.
Both Aslef and the RMT are in dispute with Govia Thameslink Railway, Southern's parent company.
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