TSSA General Secretary, Manuel Cortes, has praised engineering staff for finding hairline cracks in trains and said services must not resume until it's "one hundred per cent safe" to do so.
The issue found in the Hitachi 800 series trains, used by Great Western Railway (GWR), London North Eastern Railways (LNER) and Hull Trains has sparked major disruption to services.
All high-speed GWR services between London, Bristol, Cardiff and Penzance have been cancelled and customers are advised not to attempt to travel today. LNER is currently advising passengers not to travel.
It means limited to no service on the East Coast – between Edinburgh, Newcastle, York and London.
Manuel Cortes said:
"It’s welcome news that railway engineering staff have found these cracks before they led to an accident.
"It’s now absolutely vital that a full investigation is carried out into what led to these cracks. This rolling stock must not be allowed back into service until we are one hundred per cent certain these trains are safe.
"It’s important to point out that the affected trains are relatively new, in which case the manufacturers should foot the bill for any repairs, not passengers or taxpayers."