Train passengers trying to get home for Christmas will be hit by a reduced service after three rail operators were expected to cut their Friday timetables by a quarter.
First Capital Connect, Chiltern and Merseyrail cut up to 25% of their services on Thursday and were likely to run the same reduced schedule for Christmas Eve.
Cancellations were also expected across the rest of the network after 10 operators ran a special or amended timetable.
The Association of Train Operating Companies (Atoc) said a reduced timetable was designed to ensure scheduled services were able to run on time.
A spokeswoman said many of the alterations were just “tweaks” to the timetable while many of the services affected by the reduced schedule were commuter lines that were not expected to be busy.
But Anthony Smith, chief executive of Passenger Focus, warned people to expect packed trains on Friday as millions of Britons travelled home for Christmas.
He told the Telegraph: “Passengers should make sure they make a seat reservation to avoid the risk of having to stand for their entire journey or be turned away as carriages will be full.”
Atoc said a reduced service meant operators were more likely to keep to their timetable.
A spokeswoman said: “The vast majority of services that would normally run on a Thursday ran, and four out of five trains arrived on time. A handful of operators ran a reduced service in order to improve reliability for passengers.
“We will have to see how tomorrow pans out, but at the moment we expect services to run at a similar level. We understand passengers’ frustration when there is disruption and apologise to anyone caught up in it.”