Judges Lord Justice Singh and Mrs Justice Farbey said though they could understand why the claim was not brought until the release of the report, it needed to have been made sooner.
Mr Roussos said families had to “wait for all these reports to get the truth, and now we know the truth, we’re out of time”.
“In the months running up to the tribunal, MI5 [and] their legal team did everything they could to stop it,” he said
“For MI5 to turn around and say we cannot take this any further because you’re out of time, that’s a pathetic excuse not to hear our side and hear the evidence.”
The judge also said had the claims been allowed to continue, MI5 would have needed to divert resources to the proceedings rather than “their core responsibilities” of stopping future attacks.
“The legal action is dealt with by the legal team, not MI5 agents”, Mr Roussos said.
“You look at every court [building] and it says justice along the top, this is not justice, this is hiding.
“My family personally don’t feel justice has been served here.”
In a statement the Home Office spokesman said: “Our thoughts continue to be with all those who lost loved ones, and suffered such terrible harm, as a result of the Manchester Arena terrorist attack.”
