RMT union say they face "massive pressure" to keep services running - in the face of cutbacks.
"This shocking new picture highlights the reality on Britain's railways today - staffing, inspections and track renewals have been cut in the dash to save money and there is massive pressure right from the top of Government to keep services running at all costs regardless of the potential human cost. If we don’t reverse the cuts on Britain’s railways another major tragedy is inevitable.
"RMT has made it crystal clear that we want all cuts to staffing, maintenance and renewals reversed and all track works brought back in house rather than subbed-out to contractors. The current contractor staff should be transferred over to direct Network Rail employment. We also want the pressure from the centre to run services at any costs lifted to enable safety-critical works to take place immediately."