The union has learned that independently led formal inquiries into serious incidents, required under Railway Group Standards, will be waived by the Rail Safety and Standards Board if the employers directly involved agree that one should not be held.

“This is a huge leap in the wrong direction for railway safety,” RMT general secretary Bob Crow said today.

“Only two days ago one private-sector track worker was killed and another was injured in an incident at Trafford Park. Now we are being told that the employers have agreed that there is no need to hold a formal inquiry and can expect the RSSB to issue them a certificate of non-compliance on the nod.

“It is unacceptable that employers directly involved in serious incidents can put their heads together and request an automatic exemption from the duty to hold an independently led inquiry.

“The RSSB is effectively an employers’ organisation and there are very clear and obvious reasons why it should not have the right to overrule that obligation.

“Inquiries held under Group Standards are chaired independently, the relevant unions are entitled to observe them and they usually report within four or five months.

“Those reports usually provide crucial pointers to action needed to avoid similar accidents and the fact that the vast majority of their recommendations relate to shortcomings in management processes suggests why employers are so keen to avoid them.

“Investigations by the new Rail Accident Investigation Branch will be held behind closed doors with no oversight, union reps will be excluded, and they will be expected to report only within a year – and in any case they are no substitute for formal inquiries.

“RMT has made it clear to the RSSB that we object to this abuse of its right to issue non-compliance certificates, imposed without any consultation with us, and expect them to comply with the requirements of the Group Standard,” Bob Crow said.