Spain train disaster clouds Sánchez chances of re-election

Crucially, at one point a controller instructed a stalled train to restart, clearing it to advance at up to 160km/h (100 mph) even though a second train was stuck on the line up ahead.

The impending collision was clear from audio calls and on big screens in the control centre in Madrid.

"They worked. We checked. They could see what was happening," Puente confirmed. But the advancing train was never ordered to stop.

"I'm no judge... But these are the facts."

So would he take personal and political responsibility anyway, and resign? Puente called it his "duty", rather, to remain as minister.