A new air traffic control centre at Prestwick could be threatened by the cash crisis which is engulfing the National Air Traffic Service (Nats), an official report has warned.

Nats has lost money because fewer aircraft are flying over Britain and paying for air traffic control services, following last year's terrorist attacks on the US.

The National Audit Office (NAO) said the UK Government failed to take account of all the risks when it partially privatised the service.

In a report published on Wednesday, the NAO said that future investment in advanced computer systems and a new Scottish control centre are now at risk.

Ian Davidson warned of delays at Prestwick

The government sold nearly half of air traffic services to a consortium of seven airlines last summer, but since 11 September Nats has lost 14% of its income.

Ian Davidson MP, a member of the Commons Public Accounts Committee, said he is worried about the future of air traffic control at Prestwick.

He said: "There is a clear commitment to keep a Scottish control centre and there is no reason to believe that that change in policy has actually been made or is being suggested.

"However, there are serious difficulties about raising additional funds for the investment that is necessary in the future, and in that context a second centre in Scotland must at least be under risk of delay."

The Glasgow MP added: "The ideological commitment to part privatisation does rather seem now, a bit like Railtrack, to have blown up in our face."

Less planes are crossing the UK

The report said Nats shareholders - like British Airways and Virgin - are unlikely to bail the company out with extra money.

Mr Davidson said that means ministers may have to step in again.

In March, the government provided �30m in emergency funding, as part of a �60m bail-out.

The criticisms come the day after the government unveiled proposals for a massive increase in the UK's airport capacity to cope with what ministers believe will be a massive increase in air travel.