Ms Rice did not place blame on the FBI specifically, but said the Justice Department could not have been reconfigured to ease restrictions during the amount of time the Bush Administration had been in office.

While Ms Rice focused on a broader picture, saying there was 'no silver bullet' that could have prevented the September 11 attacks, Mr Ashcroft quickly went on the offensive, explaining in his opening statement that he had argued for changing the rules for FBI covert operations to allow for the assassination of persons deemed a threat to the country rather than only their capture.

'My formal review found no covert action programme to kill [Osama] bin Laden, only a covert action programme to capture bin Laden,' Mr Ashcroft said. 'Our agents were given only the language of lawyers.'

Also testifying yesterday were former FBI director Louis Freeh and former attorney-general Janet Reno. Mr Freeh, who stepped down six months before the attacks, has been accused of heading an organisation so adverse to information sharing that some markers of the impending plot not been followed up properly.

One memo written by an agent pointed to a number of suspicious men attending flight schools across the country and theorised that they might be planning a hijacking.

Thomas Pickard, who served as acting director of the FBI after Mr Freeh stepped down, said he did not receive information about the flight school suspicions or the arrest and release of Zacarias Massaoui, who was later charged with having a hand in the plot, until after the attacks.

Mr Freeh emphasised that there was a shortage of analysts, especially those that spoke Arabic, and a shortage of resources in general, something with which Mr Ashcroft agreed.