PASSENGERS without reservations may find themselves left on the platform this Christmas, as rail operators slim down their services while speed restrictions are in force.

York-based GNER will announce its full timetable for the festive period next week, but spokesman Alan Hyde warned "it is to be an exceptionally busy time".

A vastly-reduced service will be in operation over the Christmas period, and rail users are being warned that "it is highly likely" there may not be enough seats to go round.

"Passengers with seat reservations will be guaranteed a place on trains," continued Mr Hyde.

"But the normal walk-on service that makes rail travel so much more flexible than air travel may not be available."

He added that "contingency plans" would be in place and the company would do everything it could to get passengers to their destinations, but he stressed the need to reserve seats in advance.

The company intends to use "boarding control" at King's Cross to limit passenger numbers getting on to the platform, and standing space will be limited on trains.

GNER, which operates the London King's Cross to Newcastle and Edinburgh route, has suffered some of the worst track replacement problems since the fatal Hatfield derailment and cannot plan timetables until Railtrack provide further information about speed restrictions.

The company's Christmas train database has been taking bookings since mid-October for the services that are already known to be running - and further trains will be added next Monday when the full timetable is due to be announced.

"When normally we would be putting on as many as five trains an hour to Edinburgh we are running fewer trains than usual," said Mr Hyde.

"We are doing our best to provide as robust a service as possible in the circumstances and out timetablers will be working like fury over the weekend to get the information out as soon as we have it from Railtrack."

From today there will be a two-week period to December 18 when services would be substantially similar in frequency to last week.

That would be followed by a three week period, from December 18 to January 7, which would constitute the Christmas timetable period.