A computer failure that briefly grounded all aircraft in Britain at the peak morning time caused airport chaos on Thursday and raised further questions about the state of the country?s transport infrastructure.

The computer crash that disrupted some of Europe?s busiest airspace added to pressure on the government amid talk of a consumer backlash over soaring petrol prices and with strikes looming in the crumbling national rail network.

Prime Minister Tony Blair?s Labour government, facing local and European elections next week, blamed a lack of investment in the country?s transport system by previous administrations.

?Over decades, successive governments did not spend enough on the infrastructure and air traffic control is no different,? Transport Secretary Alistair Darling told BBC radio. But analysts and the opposition Conservatives said the problem lay with National Air Traffic Services (NATS), the organisation jointly owned by the government and the airlines which runs the country?s air traffic control system.

?This is not the first time that the travelling public have had to endure problems associated with NATS? computers,? said Conservative transport spokeswoman Theresa May.

Air industry writer Julian Moxon said money was not the problem. At root was an overloaded system plagued by software problems and out of synch with neighbouring systems.

NATS blamed the 43-minute outage that began soon after 0500 GMT on a technical failure, but said it was rapidly corrected. However, all planes were grounded during the outage for safety reasons as incoming flights were landed manually by traffic controllers, and airport sources warned of delays to flights throughout the day.