Inquests into the Manchester Arena bomb victims’ deaths may be replaced by a public inquiry on national security grounds.
It follows a decision by the coroner that sensitive intelligence evidence should be kept secret.
Sir John Saunders ruled yesterday its disclosure could “assist terrorists” planning similar attacks.
He said he had agreed to applications from the Home Office and counter terror police for public interest immunity, which would stop such sensitive material being made public.
An inquiry would be able to hear the evidence in closed sessions, with families and the press excluded.
Solicitor Elkan Abrahamson, who represents three families said they want “the maximum transparency”.
He added: “Public interest immunity must not be allowed to stop the truth coming out, in particular where there are failures by MI5 and police.”
Suicide bomber Salman Abedi killed 22 people and injured hundreds at an Ariana Grande gig in May, 2017.
The inquests had been due to be heard next April. A final decision is expected next month.
The Home Office said: “It is vital we learn lessons, whatever they may be.”