Immediately following the accident, it was reported that one of the two drivers had gone through a red signal, causing the collision. Vervotte and Descheemacker responded that an investigation was under way and warned against speculation as to the causes of the accident.

However, by the start of this week it was being reported as “99.9% certain” that the cause was indeed what the rail industry calls a Signal Passed at Danger (SPAD). According to experts who have examined data from the signalling centre at Brussels’ South Station, the light had been red for a few minutes before the train from Leuven to ‘s Gravenbrakel passed.

If Belgium’s railways had been equipped with the safety systems they promised to install after the last major rail crash in 2001, the driver’s alleged error need not have led to a crash. Following the rail accident in Pécrot in 2001, the NMBS promised the swift introduction of a safety system called ERTMS, which cuts the power to any train involved in a Signal Passed at Danger. But last week it was revealed that, nine years later, only 25% of tracks are fitted with the system, and only 1% of trains. Over the entire network, only one train in 400 combines both essential elements.

The trains are the responsibility of the NMBS, while the tracks fall under the control of Infrabel. Both pushed responsibility for the delay onto the European Union and the lack of standardised norms; the EU quickly responded with a flat denial. The ERTMS system has been available since 2000 and is already in operation in other EU countries, said rail expert Christian Faure of the EU Commission.

Countries like the Netherlands and Germany, however, rely mainly on other systems to ensure rail safety. This is what Belgium decided to do in 2006, minister Vervotte said, but not before five years of inactivity which she blamed on “insurmountable technical problems”.

According to John Baggen, a public transport specialist from the Technical University of Delft, Belgium has its own system designed to react in cases of Signal Passed at Danger, known as TBL, which in 2007 had been fitted to 1,800 signal locations of the 8,700 on the network. TBL is compatible with the European ERTMS system and, therefore, could easily remain in operation while troubles with ERTMS are sorted out. The NMBS has a target for half of all signals to be equipped by the middle of this year, with the entire network up and ready by 2012.

Minister Vervotte has now said the government would be willing to move faster on installing safety systems, though it’s not clear which one. “The impression people are now giving is that a system is standing ready on the shelf that can be bought like in a supermarket. That’s not the case,” said Vervotte on the Sunday political programme De zevende dag. However, she will now be investigating whether speedier progress could be made. Not only would the decision have budget implications, she said, it would also have an impact on services, with some trains having to be withdrawn or stations closed.

• Last week it was revealed that the driver of the Leuven train, who allegedly ran through a red signal, made a similar mistake a year ago and was suspended for several days before returning to work under supervision. On that occasion, no casualties were involved. The driver has been interviewed by police and maintains that the signal was green.