Solicitor Louise Christian acted for the bereaved families

The company is facing an unlimited fine after admitting health and safety breaches, but sentencing has been adjourned to 18 December.

Relatives of three of the dead called the adjournment yet another example of "prevarication" by Network Rail.

Linda Di Lieto, who lost her son, said: "It seems it is just a game to them."

Ms Di Lieto's son, Sam, a 24-year-old Cellnet sim designer manager, from Bloomsbury, central London, was killed when the Thames Trains train he was travelling on passed a red signal and hit a Great Western express.

After attending Tuesday's hearing she asked: "How many times can they keep delaying? This has been going on for seven years.

They have put all the bereaved families through torture Maureen Groves, Bereaved mother Network Rail admits crash errors

"But we are going to stick this out. We are not going to vanish."

At London's Blackfriars Crown Court, judge Aidan Marron QC adjourned sentencing until 18 December, when Network Rail, which owns and operates the entire rail infrastructure, will indicate the full basis of its guilty plea in writing.

Nigel Sweeney QC, defending, had asked for the adjournment to allow time for a mass of "unused material" to be examined.

Legal costs

But Maureen Groves, whose daughter, Juliet, 25, a chartered accountant from Chiswick, west London, was also on the three-carriage local service, said: "They are playing for time, just trying to wear us down.

"The legal costs of all this must be staggering and could have gone on making the railway safer.

"They have wasted so much money and they have put all the bereaved families through torture."

Railtrack killed my daughter Robin Kellow, Bereaved father

Robin Kellow, whose daughter, Elaine, 24, an IT worker from Paddington, central London, was also among the fatalities, said: "Railtrack killed my daughter. Everybody knows they did."

A Network Rail spokesman 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."

Public inquiry

The introduction of a Train Protection and Warning System that applies a train's brakes if it is approaching a red signal too quickly to stop had "greatly reduced the risk of an accident", the statement added.

"This change, along with many others, has helped to make rail travel today the safest form of transport."

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 Solicitor, Louise Christian

But Louise Christian, a solicitor who acted for bereaved families of Ladbroke Grove, said: "The sad thing is that Ladbroke Grove could happen tomorrow because the crucial recommendations of Lord Cullen on train protection systems were not implemented by the government."

Thames Trains and Railtrack were both criticised in a public inquiry report by Lord Cullen.

On Tuesday Ms Christian said Railtrack had denied responsibility throughout the public inquiry.

"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," she added.

Keith Norman, general secretary of train drivers' union Aslef, said it was "appalling" that the company's "managers and decision-makers can stroll off without a care in the world".

We hope that the court uses the full range of sentences at its disposal when they come to sentencing Aslef general secretary Keith Norman

The union demanded a "complete review of how the infrastructure is overseen" and is calling for corporate manslaughter laws to be strengthened.

"We hope that the court uses the full range of sentences at its disposal when they come to sentencing," Mr Norman added.

Jonathan Duckworth, the chair of a survivors group, told BBC News: "We would like to see a very, very large fine... that actually will affect, possibly affect, the viability of the company."

He added: "That is the way to make companies treat health and safety legislation with the respect it should have."

But Liberal Democrat transport spokesman Alistair Carmichael said: "Removing a large sum of money, in the form of a fine, will do the network no good at all.

"Network Rail should not be punished too harshly for the actions of its predecessor."