Tens of thousands of travellers could be stuck in the country or on the Continent due to cancelled Eurostar trains on Boxing Day.
Eurostar has had to cancel all 43 trains linking London and Paris, Brussels and Amsterdam the day after Christmas.
The cancellations have been announced even though none of the train company's staff are on strike.
Instead a strike by RMT union staff has been blamed for the change of service.
The High Speed One line between London and the Channel Tunnel at Folkestone will be closed from 6pm on 24 December to 6am on 27 December because signal workers are on strike.
Bertrand Gosselin, chief operations officer at Eurostar, said: “We know how important it is for our customers to be able to travel at this time of year, and as a business we always prioritise all services running over the festive period.
“We have left no stone unturned in our efforts to be granted access to the UK high-speed line on Boxing Day – as we have been on every other RMT strike day this year – and made it absolutely clear the impact this will have on those who were booked to travel.
“We share our customers’ frustration and disappointment and we will do all that we can to run extra services when the line is open to give passengers more flexibility.”
Eurostar has issued advice to passengers who find themselves unable to travel on Boxing Day.
They can exchange their booking for free to travel at a different time/date in the same travel class, subject to availability.
Clearly this will not be helpful for those who need to travel on December 26, as there are no other trains running that day (rail services usually don't run on Boxing Day across the UK).
Customers can also cancel their booking and claim a Eurostar e-voucher which will be valid for 12 months.
Alternatively, passengers can cancel their booking and claim a refund from where they originally bought their ticket.
"Please do not go to the station unless you have exchanged your ticket on to a train which is due to run," a spokesperson for Eurostar said.
If you do need to get into or out of the country on Boxing Day and were booked onto a Eurostar, Le Shuttle is an alternative option.
The train service runs from Folkestone, Kent to Calais - will continue to run as normal, unaffected by strikes.
You can book a trip with Eurotunnel Le Shuttle from £82 per vehicle (up to 9 passengers) each way for a Short Stay Saver ticket, which is valid for five calendar days.
Flying is an option, but is not a means of transport for the faint of heart over Christmas.
PCS union Border Force workers are striking on December 26, meaning long waits at security or at the passport gates are likely.
