Thousands of bank holiday weekend rail travellers were braced for disruption today after damage to overhead power lines halted services.
Network Rail investigators were last night trying to establish the cause of damage to four power lines, which forcing the cancellations of services in both directions between Grantham, Lincolnshire, and Peterborough, Cambridgeshire.
It caused major disruption for travellers on the east coast main line, which runs between Aberdeen and London's King's Cross.
Service operator East Coast said the damaged lines caused disruption to 70 of its 102 scheduled services. A Network Rail spokesman said it would be "all hands on deck" overnight to fix the damage in time for this morning's timetable.
The spokesman added: "A few of the very early morning services may be affected but we are expecting to be back to a full timetable by around 9am."
Network Rail had hoped to resume a limited passenger service, using diesel trains, on two of the four affected lines last night.
Network Rail engineers spent much of yesterday working to resolve the problem and were "hopeful" that a normal timetable would be resumed today.
A spokesman said around 200m of overhead equipment had been damaged, adding: "There is a lot of damage that needs to be repaired."
He said the damage could have been caused by a number of things including a technical problem with the lines, vandalism or even a carrier bag becoming entangled in the overhead wires.
The damage to the lines became apparent at around 10.20am yesterday. Passengers were advised to use alternative routes.
It was a chaotic start to the bank holiday weekend for holidaymakers and came as football fans were travelling into the capital for last night's Champions League final between Barcelona and Manchester United at Wembley.
Replacement shuttle bus services were running throughout the day between London King's Cross and Peterborough, and between Grantham and destinations north.