Travel industry bosses are queuing up to lambast the government for its handling of the ash crisis after it admitted a blanket ban on flying may have been ‘too cautious’.

Tui Travel chief executive Peter Long used the word ‘shambles’ while Ryanair boss Michael O’Leary described it as a ‘balls up’.

Long said: “The government’s response to the crisis has been a shambles. It is clear that they underestimated the severity of the consequences of the decision for a blanket closure of the airspace for such a protracted period.”

O’Leary defended Ryanair’s refusal to pay stranded passengers’ expenses, arguing that governments were to blame for the extent of the disruption.

He said: “Why exactly are the airlines expected to be reimbursing people’s hotels, meals and everything else when the governments are the ones who made a balls up of this?”

Secretary of state for transport Lord Adonis conceded that the flight ban was over-cautious. Speaking to the BBC, he said: “I think it’s fair to say that we were too cautious, but ‘we’ being the international safety regulation community.”

Virgin founder Richard Branson joined airline bosses in insisting that airspace could have been opened sooner.

“If they’d sent up planes immediately to see whether the ash was actually too dangerous to fly through, or to look for corridors where it wasn’t very thick, I think that we would have been back flying a lot sooner,” he said.

Airlines are furious after rivals in Germany, France and the Netherlands were able to fly on Tuesday many hours before British airspace opened up.

Thomas Cook chief executive Manny Fontenla-Novoa urged the government, the CAA and air traffic control body Nats to agree defined procedures and undertake proper co-ordination across EU airspace to ensure the situation “can never occur again”.

Conservative Leader David Cameron has called for an inquiry into the decision to reopen airspace when atmospheric conditions had not changed.

The government has denied the decision to re-open airspace came after pressure from airlines. However, the decision was taken after carriers conducted test flights, with BA putting 28 long-haul flights in the air on Monday heading for Europe.

Although some European airports such as Madrid were open, the decision to allow the flights to land in the UK was taken while they were in the air.