The Transport Secretary today admitted that the Government had been “too cautious” in its decision to keep British airspace closed for six days, as criticism of the blanket flying ban increased.

Speaking on BBC radio Lord Adonis said: “I think it’s fair to say that we have been too cautious. ‘We’ being the international safety regulators”.

Britain was among the last European countries to lift flying restrictions as the first flight touched down at Heathrow just before 10pm last night.

The airline industry lobbied strongly for an easing of controls since the weekend, citing evidence from test flights that showed aircrafts’ engines had not been damaged by the ash.