Rail passengers endured more morning misery today when an overhead line problem led to major disruption to key services.
On the East Coast line - a vital London to Scotland route - no trains were able to run between London and Peterborough during the morning rush-hour.
There were reports that scores of passengers had been left stranded at London's King's Cross station overnight after the last train to Leeds was cancelled.
One passenger said travellers had been put on a coach to Peterborough at 3.40am but that it had been involved in a minor accident in Huntingdon in Cambridgeshire.
Some of those stranded are thought to have been Arsenal supporters on their way home from their club's European Champions League match with Bayern Munich.
The latest overhead line problem is at St Neots in Cambridgeshire and is affecting a number of train companies.
On First Capital Connect, buses replaced trains between Biggleswade and Peterborough, with journey times extended by up to 60 minutes
Grand Central and First Hull Trains' services were unable to run between Peterborough and King's Cross, but it was hoped that a limited East Coast service would be able to operate between Peterborough and King's Cross after 9.30am.
Today's problem follows last night's electrical supply problem that hit services in north London as well as an overhead line problem last week at Radlett in Hertfordshire that led to severe disruption.
Bob Crow, leader of the RMT transport union, said today: "We have been raising serious concerns about the shortage of overhead line (OHL) crew and capacity onBritain's railways for a number of years now.
"We repeated those points only last week when the lines came down at Radlett and now just days later we have another massive OHL failure on our hands. We cannot carry on like this."
He went on: "The chaos on services hitting hundreds of thousands due to cancellations out of central London as a result of the lines down overnight reinforces RMT's demand for a full review of OHL maintenance and emergency staffing numbers and capacity to cope with this growing infrastructure issue and a massive backlog of essential works. ".