Triumphal launch of Spain's new rail link sunk by safety fears

The first paying passengers step on board the high-speed train that connects Madrid to the Catalan city of Lleida today, on a line that will eventually reach Barcelona. The €7bn (£5bn) link, Spain's biggest engineering feat for a century, will revolutionise travel between its two main cities and galvanise the fortunes of towns along the route.

King Juan Carlos joined the inaugural trip yesterday, which was a year late and at half-speed. All the triumphal razzmatazz could not squash criticisms that the 468km (290 miles) of track may be mortally unsafe. The Ave, the Spanish acronym that means "bird", averaged a sedate 175kph (108mph), far short of its vaunted 350kph.

The project has been delayed five times. Many stations are half-finished, the experimental RTMS signalling system isn't ready and there is no coverage for mobile phones. But the most serious problem is the threat of potholes.

The line between Zaragoza, in mountainous Aragon, and Leida, crosses unstable terrain of clay and gypsum prone to sudden collapse. Engineers have spent 18 months filling in five craters that yawned overnight near and under the track. The latest cavern is 15 metres deep and appeared a week ago a few hundred yards from the rails. The rail authorities guarantee that the track will not collapse, saying that the holes are not dangerous.

But Joaquin Lahoz, head of Aragon's College of Geologists, said: "I will not be taking the train and neither will my family." Safety measures were insufficient and inadequate, he said.

Francisco Alvarez Cascos, the Public Works minister, denies work has been botched to complete in time for election campaigns. He blames the holes on works by regional and local authorities.

Comparisons have been drawn with the Ave link with Seville. That is Spain's jewel: it runs smoothly, is never late, is always full and makes huge profits. But Mr Cascos reckons it may be a year or two before you can glide between Madrid and Barcelona in just two hours 40 minutes.