More than 250 people join group action claiming security service failed to take steps that could have prevented 2017 bombing
Hundreds of the Manchester Arena bombing survivors, along with relatives of the victims, have launched legal action against MI5, claiming it failed to take action that could have stopped the attack.
More than 250 people have joined the group action against MI5, and have submitted their claim to the investigatory powers tribunal, which hears complaints against intelligence services.
