The MI5 and the police will be cleared of making serious mistakes which allowed terrorist to strike Britain in four attacks this yea, The Guardian reports.
Internal reviews in both organisations found no clear chances were missed to prevent atrocities which killed 36 people.
But the reviews will also make a series of recommendations to minimise the chances of missing future attackers, including a new computer algorithm to detect behaviour that could indicate involvement in terrorism.
The internal inquiries were set up in the wake of the attacks and have been carried out by MI5 and the police themselves, overseen by a barrister.
The reviews have found information was received by MI5 about the Manchester attacker, Salman Abedi, which could have been given a higher priority.
But that conclusion is reached with the benefit of hindsight, sources say, and nothing in the reviews demonstrates that clear chances were missed to stop any of the attacks that killed 36 people.
Some may see the notion of MI5 and the police investigating themselves as unsatisfactory; parliament’s intelligence and security committee (ISC) have been unable to investigate because the prime minister failed, until last week, to establish it after the May 2017 election.
The ISC will meet on Tuesday to consider if it should hold its own inquiry into the attacks in London and Manchester.
The report concerns attacks in Westminster, Manchester, London Bridge and Finsbury Park.
The reviews into the four atrocities between March and June where perpetrators beat Britain’s defences were overseen by a barrister, to provide assurance to the government that the inquiries were thorough.
No individuals are criticised in the reports, and that includes MI5 director-general Andrew Parker.
Some media reports had claimed the inquiries into the attack would be so damning that his job might be in jeopardy.