The final report of the Inquiry into the Manchester Arena terror attack in 2017, that killed 22 people and injured hundreds, has shown that MI5 failed to act on crucial intelligence in a “significant missed opportunity”.

Chair of the Inquiry, Sir John Saunders, said there was a “realistic possibility” that investigators could have intervened if they had acted more decisively on two key pieces of evidence in the run up to the attack.

The 207-page report found that:

• If MI5 had taken key pieces of intelligence more seriously in months before the attack, Abedi’s return from Libya four days beforehand would have been taken “extremely seriously”.
• If an investigation had begun on his return, the security service could have found Abedi’s homemade device, that he was storing in a car in Manchester, which “might have” been enough to prevent the attack.
• MI5 failed to share two significant pieces of intelligence with counter-terrorism police in the time before the blast, in what Saunders referred to as a “communication breakdown” between the two agencies.
• While Abedi’s family hold “significant responsibility” for his extremist beliefs, he should have been referred to Prevent, an anti-radicalisation scheme, up to two years before the attack.

While the report does not describe the nature of the two pieces of intelligence, it does reject a previous claim by the security service that they related to “non-terrorist criminality” by Abedi.

The report also detailed that one MI5 officer, Witness C, believed the second piece of intelligence could be of “pressing national security concern”, but failed to raise the alarm promptly. It said that the agent should have raised concerns immediately and written a report on the same day but did not do so.

Saunders said “Based on everything the Security Service knew or should have known, I am satisfied that such an investigative action would have been a proportionate and justified step to take. This should have happened.”

The report concluded: “The delay in providing the report led to the missing of an opportunity to take a potentially important investigative action”. This was significant, Saunders said, because the intelligence gave rise to the “real possibility of obtaining information that might have led to actions which prevented the attack”.

Nicola Brook, a solicitor from Broudie Jackson Canter who represents five victims’ families, said:

The families who lost loved ones note that the report has acknowledged that there were significant failings by security services and that this tragedy might have been prevented if the security services had done their job properly.

Throughout the Inquiry, M15 maintained that no one else was knowingly involved in the attack. However, the Chair has found that it is likely that there were others knowingly involved in plotting a bomb. He also found that it was likely that Salman and Hashem Abedi received instruction to make an IED in Libya in 2016. He said there was a “material possibility” that Salman Abedi acquired the switch that detonated the bomb in Libya and that it was possible that he was carrying the switch with him when he returned to the UK via Manchester Airport on the 18th May 2017. The families believe that had he been stopped on entry to the UK it is likely that the plot would have been discovered or disrupted.

It is disappointing that the families will never know the full truth of what happened. All of the families signed an undertaking not to reveal confidential information which they have not breached. They, above all others, are entitled to know what the security services knew and had the most interest in keeping it confidential.  

We also note that additional information wasn’t available to Lord Anderson in his Post Attack Review and was only available to the Chair after he pursued it. This is why we are campaigning for the introduction of a Hillsborough Law to ensure public officials have a duty to tell the truth to public inquiries or face criminal action.

Andrew Roussos, whose eight-year-old daughter Saffie-Rose was killed in the blast, said:

Our beautiful little girl lost her life because of the failings of the security services and today’s report acknowledges that MI5 might have prevented the bombing.

We all heard the evidence and knew there were failings, but hearing how this tragedy might have been avoided is devastating for us all. This was a cataclysmic failure, and it is clear from all of the evidence we have heard about Abedi that there were many opportunities for the security services to have ensured the bombing never happened. In my view the fact that MI5 failed to stop him despite all of the red flags available demonstrates they are not fit to keep us safe and therefore not fit for purpose.