The committee’s report went on to address the lowering of the threat level from severe general to substantial just prior to the attacks. This was investigated at the time, without significant result. However, after the attacks the source identified one of the men as Khan. Khan also spent time there with Tanweer from November 2004 to February 2005, the report said. The ISC also revealed details of another report from a source which was given to the security service in February last year, several months before the bombings The report apparently stated that a man had travelled to Afghanistan in the late 1990s/early 2000s with another man and that both held extremist views. But the extent to which the attacks were planned, directed or controlled by contacts in Pakistan or elsewhere remained “unclear”, the committee said.

The report also said the intelligence and security agencies currently have “no evidence” of direct links between the July 7 attacks and four further failed attacks on London transport targets on July 21. The report revealed that after the July 7 attacks Khan was identified as one of a number of men from the UK who had travelled to Pakistan in 2003 and sought meetings with al Qaida figures. The report said the security services have discounted the theory that a terror mastermind fled Britain shortly before the attacks. There is no intelligence to indicate there was a fifth or further bomber, it added. The report revealed that in a review of its records after the attacks, the security service MI5 found it had a telephone number belonging to July 7 bomber Germaine Lindsay on file. “Greater coverage in Pakistan, or more resources generally in the UK, might have alerted the agencies to the intentions of the July 7 group.” The MPs warned that even if the security services go on to carry out more intrusive work to combat the terror threat it seems “highly unlikely” that it would be possible to stop all terror attacks.

In a key passage of the report, the committee said: “The story of what was known about the July 7 group prior to July indicates that if more resources had been in place sooner the chances of preventing the July attacks could have increased. Improvements made since July 7 to the intelligence and security agencies had shown that there “had been room to do more and to do it more quickly than had been thought possible at the time”. However, it added: “Nonetheless we conclude that in light of the other priority investigations being conducted and the limitations on security services resources the decisions not to give greater investigative priority to these two individuals were understandable.” The committee recommended a revamp of the terror alert system but said it should recognise the limitations of intelligence gathering and that attacks may be at the planning stage without being detected. “We recommend that these limits are reflected in a more standardised and formalised way within the threat level system and in all threat level reports,” it said. “This will help avoid inappropriate reassurance about the level of threat in the absence of intelligence of a current plot.” Regarding the “home-grown” terror threat the committee said it was “concerned that more was not done sooner”.