More than 250 survivors and relatives of victims from the Manchester Arena bombing in May 2017 have initiated legal action against MI5, alleging the agency’s negligence in handling intelligence could have prevented the attack. This represents the first time MI5 has faced a lawsuit regarding its response to a domestic terror incident. The case has been filed in the Investigatory Powers Tribunal (IPT).

The lawsuit follows findings from a public inquiry into the attack, which identified missed opportunities by MI5 to act on intelligence about the bomber, Salman Abedi. The inquiry uncovered that despite multiple signs of Abedi’s potential threat, including his travel to conflict areas, MI5 failed to take sufficient action that might have obstructed the planning of the attack.

The attack itself, carried out by Abedi, occurred during an Ariana Grande concert and resulted in the deaths of 22 people, leaving hundreds injured. It stands as one of the deadliest terror attacks in the UK since the 2005 London bombings.

This legal action is supported by several law firms, including Hudgell Solicitors, Slater & Gordon, and Broudie Jackson Canter, representing the affected parties seeking justice and accountability for the failures identified. MI5’s Director-General, Ken McCallum, has previously expressed deep regret over the agency’s shortcomings in preventing the attack.

As legal proceedings continue, MI5 has abstained from commenting directly on ongoing cases. The outcome of this legal challenge could have significant implications for the accountability and operational procedures of UK intelligence services.