People travelling for Christmas face "quite severe" disruption as strong gales and torrential rain are set to cause travel chaos - with one transport boss saying "It won't be an easy task".
Severe weather warnings are in place for much of the UK including the East of England, threatening to cause localised flooding across southern England and Wales.
Strong winds are expected, with speeds of up to 80mph in coastal areas of southern England, while Scotland is set to see some snowfall, the Met Office said.
The Department for Transport said the unsettled spell of weather will continue for the rest of the week.
Emma Compton, a forecaster at the Met Office, said: "The disruption to transport could be quite severe."
Robin Gisby, managing director of operational services for Network Rail, said the next couple of days will be a challenge.
"Our fundamental concern over the next 48 hours is to get everyone where they want to be for Christmas."
By lunchtime on Monday, rail services in the Anglia region were already facing cancellations and delays.
Greater Anglia, which operates trains in Cambridgeshire, Essex, Norfolk and Suffolk, said it didn't expect to run any trains before 10am on Christmas Eve so it could check lines for damage during daylight.
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