Rail operators claim the covid-19 pandemic has led to staff shortages and caused widespread train cancellations in the run-up to Christmas.
It comes after a number of railway firms have begun running reduced timetables as many workers are either sick or isolating.
Rail provider CrossCountry announced it is "expecting widespread disruption to our services this week". Read more: Travellers are being urged to move their journeys forward to avoid disruption.
The company has been forced to cancel dozens of trains each day while many others have fewer carriages than usual. Among the routes affected by the cancellations include Manchester to Bournemouth via Birmingham; Bristol to Paignton, Devon; Cardiff to Nottingham; and Birmingham to Stansted