National security officials did not fully understand the ramifications of scrapping Britain's Nimrod fleet, a former defence minister has warned.

Sir Gerald Howarth said destroying the planes, which had a base at RAF Kinloss, which were under development but not completed and delivered, after the Strategic Defence and Security Review had left the biggest capability gap across the UK's defence structure.

Sir Gerald said the decision was not taken lightly but stressed the Ministry of Defence was not the only player in the decision.

He said: "I said to the National Security Advisor, Sir Peter Ricketts, does the National Security Council understand the significance of the loss of this capability? I was told 'Oh, I don't think you need to worry, minister, I think they're fully aware'.

"Well, frankly, I do not believe people in the Government have been fully aware of the significance of this loss."

Defence Minister Andrew Robathan defended the move, describing Nimrod as "one of the worst procurement disasters" he had experienced.