Rail travellers are facing yet more disruption as Southern conductors begin a further three-day strike at midnight.
Parent firm Govia Thameslink (GTR) has urged people to check travel information because some New Year’s Eve services will finish early.
The rail operator is in dispute with the RMT and Aslef unions over changes to the role of guards on new trains.
The RMT is staging the latest 72-hour walkout after months of strikes. Another strike is set for 9 January.
Southern’s deputy chief operating officer, Alex Foulds, said: “Our best advice is to check on the day you travel, particularly if you are heading out to new year celebrations, as services on some routes finish early in the evening.
“We are sorry that yet again passengers will have their plans disrupted by what is pointless industrial action. Our door remains open for meaningful talks.”
Train drivers, represented mostly by Aslef, will strike for a further six days from 9 January, when most routes are expected to have no services.
RMT general secretary Mick Cash said: “The solution to this continuing chaos is in the hands of GTR and the government.
“If the owners, the Go Ahead Group, spent a fraction of the millions they are stockpiling in profits and dividends on staffing and safety, this dispute could be resolved overnight. RMT remains available for talks.”
The RMT has previously accused Southern of “hoarding profits” but the rail operator said it made a loss last year and would not make any profit this year.
During the last drivers’ strike, Aslef went into talks with GTR at conciliation service Acas, but Mr Cash said he was not allowed in.
The negotiations ended without a deal.
Politicians and campaigners called on the government to intervene, but the Department for Transport said the dispute was between Southern and the unions and “not something the government is involved in”.