TRAINS between London and Glasgow could be forced to operate in "grey primer" over the Christmas holidays as the handover of a passenger franchise from Virgin Trains to First Group is held up by a legal challenge, a union has claimed.

The Rail Maritime and Transport (RMT) union said the Government-owned company now likely to take over West Coast rail services on an interim basis from December 9 had "no schedule" in place for rebranding the train fleet or staff uniforms and that their appearance would make them a "global laughing stock".

Its claims were rejected by Virgin Trains, though a spokesman for the company confirmed its branding would be entirely removed from the trains before the handover date. It is not yet clear what branding, if any, would be put in place if the service is temporarily renationalised.

Virgin, which has operated the flagship cross-border service since 1997, lost out to Aberdeen-based First, Britain's biggest rail operator whose franchises include ScotRail, in a com- petition to hold on to the rail franchise until 2026.

The decision provoked a furious response from Virgin boss Sir Richard Branson and a formal legal challenge was tabled by the company last month, leading to the agreement with First being put on hold.

Directly Operated Railways (DOR), the Government-owned company initially set up to take over rail passenger services on the East Coast Main Line in 2009, has set up a management team to run services on the west coast route from December 9 if the legal dispute is not resolved.

Bob Crow, general secretary of the RMT, said: "With the judge not even likely to decide on whether or not Virgin have a case for judicial review until mid-October, and that decision then likely to be subject to further legal challenge, this fiasco, rooted in the crazed world of rail privatisation, could drag on for months.

"It's time for the Government to end the uncertainty for passengers, and the 3200 West Coast staff, and to announce renationalisation, with effect from December 9, right now."

However, First expressed optimism that the legal dispute could be resolved ahead of the due handover date. A spokesman for the company said: "We anticipate a prompt hearing so that the unjustified challenge can be dealt with.

"Our preparations to take over the route on December 9 continue."

Although the Department for Transport usually allows 120 days for the handover of rail franchises from one operator to another, both First and Virgin said that "mobilisation" work was already under way so it would not necessarily take that long. The spokesman for First confirmed talks had also taken place with DOR in the event that it takes over the services.

A spokesman for Virgin Trains said its fleet of electric Pendolino trains and diesel Voyagers would have the Virgin logos removed as well as the Virgin shield on either end of the train and some glass panes.

"What will be left is a silver train with some red and white on the end. There is no question of them having to be repainted," the spokesman said.

A Department for Transport spokesman said: "We are taking appropriate steps in enhancing our contingency plans, ensuring that passenger services will not be affected and that there will be a safe and financially responsible handover."