The traditional Christmas shutdown of the nation’s railways began early for tens of thousands of rail passengers, with a main London terminus closed for six days. Paddington is closed from 24 to 29 December, as Network Rail undertakes its biggest-ever programme of Christmas engineering work.

A trickle of baffled passengers arrived at Paddington station, most of them foreign visitors planning to take the train to Heathrow. They were told to take the Tube instead.

Passengers from London to South Wales, Bristol and the South West were redirected to Ealing Broadway, a suburban station in west London. About half the normal number of inter-city services were running.

There are also big projects taking place between now and the New Year in the Manchester area, in South Wales and on the line from Norwich to London.

A Great Western Railway spokesman said: “One of the reasons Network Rail carries out key engineering projects during the Christmas period is that it coincides with a significant drop in demand for rail services, so the work inconveniences the fewest customers possible.”

But he held open the possibility that future Christmas timetables could include services on both 25 and 26 December. “We are open to doing so in the future, should the current level of predicted demand increase to sustainable levels.”

For most of the 20th century, trains ran on both Christmas Day and Boxing Day.

Mark Carne, chief executive of Network Rail, said that for the vast majority of the railways, trains could run on December if the operators choose to do so:

“90 per cent of the network is open. But no trains run on Christmas Day – and that’s a decision taken by the train operating companies.”

A spokesman for the Rail Delivery Group said: “Operating a normal train service on Christmas and Boxing Day would cost the taxpayer money as only a fraction of the normal number of passengers would be travelling. It would also make it harder and more expensive to carry out vital engineering work as part of our Railway Upgrade Plan of over £50bn.”

However, both Megabus and National Express are planning their biggest-ever schedules of inter-city and airport coaches for Christmas Day.

The only domestic flights on Christmas Day are two round-trips between Heathrow and Manchester, but many international services are continuing as normal – with a number of UK airports expecting their busiest 25 December ever.

A strike planned by some British Airways cabin crew at Heathrow for Christmas Day and Boxing Day has been called off.

But pilots working for Virgin Atlantic have started a work-to-rule in a dispute over union recognition. They say they will work “strictly to contract”, which could involve refusing to be flexible in the event of disruption. Virgin Atlantic said it expects flights to be unaffected.