Taxpayers and rail passengers will pay an "unlimited" fine for the blunders committed by Railtrack which led to one of Britain's worst rail disasters.
Network Rail, the state-backed organisation which took over from the private sector Railtrack, yesterday admitted there had been a catalogue of errors that contributed to the Ladbroke Grove crash in 1999 in which 31 people died and 400 were injured.
While the new infrastructure company pleaded guilty to "contributing" to the crash, it did not accept full responsibility or "causation".
Sources close to the Network Rail argued that the primary cause of the accident was the failure of driver Michael Hodder to stop at a red light as he drove a Thames Trains commuter service out of Paddington station. In 2004 Thames Trains admitted failing to train Mr Hodder properly and was fined £2m.
Peter Rayner, a consultant to the inquiry into the disaster, said Network Rail should admit "setting a trap" for drivers at Ladbroke Grove. He pointed out that eight other drivers had driven through signal SN109 while it was set at red in the six years before the tragedy.
In his report into the disaster Lord Cullen said there had been a " lamentable failure" on Railtrack's part to respond to recommendations of inquiries into two previous serious incidents at the signal, which was badly sited.
Yesterday sentence was adjourned to 18 December to give the defence an opportunity to examine a mass of "unused material".
The present rail infrastructure company is a "not for profit" organisation with no orthodox shareholders and so the fine will be paid out of funds supplied by the Exchequer and by passengers through rail fares.
Nigel Sweeney QC, defending, told a 20-minute hearing at London's Blackfriars Crown Court that he had been instructed to enter a guilty plea to various breaches of the 1974 Health and Safety at Work Act.
Network Rail admitted failing to ensure "so far as was reasonably practicable" the safety of passengers.
The charge, covering two A4 sheets of paper, said the signal was not properly sited and that its configuration could be "found nowhere else in the UK".
It went on to criticise Network Rail Railtrack Plc at the time for failing to take any measures to deal with the problem.
Bereaved relatives attending the hearing criticised the adjournment as yet another example of "prevarication" by Network Rail.
Her son, Sam, a 24-year-old designer manager, from Bloomsbury, central London, was killed on the Thames train which collided with an oncoming Great Western express.
"How many times can they keep delaying? This has been going on for seven years. But we are going to stick this out, we are not going to vanish."
Louise Christian, a solicitor who acted for bereaved families, said: " Seven years afterwards and, after years of denying responsibility including throughout the public inquiry, Railtrack has finally accepted some sort of blame.
"The problem is they have pleaded guilty in a forum where there can be no proper accountability because the only penalty is a fine against a company heavily subsidised by the taxpayer."
A spokesman for Network Rail said: "The Ladbroke Grove tragedy was a terrible event for everyone involved.
"Lessons have been learnt and the rail industry has changed enormously for the better over the past seven years."
He pointed out that the tragedy happened before the Train Protection and Warning System (TPWS) became available. The system automatically applies a train's brakes if it is approaching a red signal too quickly to stop. Figures released yesterday showed that the number of trains passing danger signals this summer increased compared with summer 2005.
There were 94 instances of signals passed at danger (Spads) on Britain's mainline railways in July-September this year eight more than in the same period last year, the Office of Rail Regulation (ORR) said.Reuse content