Tragedies like the Potters Bar train crash will recur if proposed cost-cutting measures are introduced on the railways, unions warned before the 10th anniversary of the disaster.
The Government is considering a Department for Transport-ordered report containing a number of options for cash-cutting across the UK rail network.
But transport unions say that if recommendations made in Sir Roy McNulty's review are implemented, they would spell the break-up of Network Rail and an end of its not-for-dividend status. The result, they say, would be profit being put before safety.
This Thursday's anniversary of the Hertfordshire crash that claimed seven lives should serve as a "wake-up call" to ministers, the Rail, Maritime and Transport (RMT) union boss Bob Crow said.
"Once again rail services are going to be run for profit, setting up the same poisonous set of conditions that led to problems in the past," he said. "If profits are the motive then repairs and maintenance work doesn't get done because people want to maximise returns for shareholders. This is what happened in the run-up to previous tragedies.
"We think the result will be further unnecessary deaths and injuries on the railways. The anniversary of the Potters Bar crash is a wake-up call 10 years on for the Government to look again and realise this is not the way to run a railway."
The report says it is "vitally important" that infrastructure managers and train operators have a "commercial interest in each other's costs and revenues", suggesting one way of doing this would be through joint ventures or alliances between Network Rail and train operators.
Simon Weller, national organiser of train drivers' union Aslef, said: "The system failures from Potters Bar are now being reintroduced into the rail industry by driving costs down and outsourcing work. This is how we ended up in the whole Potters Bar mess. We'll probably see more Potters Bars because the profit motive has been reintroduced into track, signalling and infrastructure work."
But Transport Minister Theresa Villier stressed the Government took rail safety seriously. "Our railways are as safe as they have ever been and the Government is clear that this good record needs to continue," she said. "The Office of Railway Regulation has a defined role in scrutinising the work Network Rail does to ensure passenger safety and both the regulator and the Government take rail safety very seriously.
"It is vital that we reform the industry and drive down costs to get the more efficient service passengers and taxpayers deserve. Eliminating waste and inefficiency through smarter working can be done without jeopardising safety."