A public inquiry into the Manchester Arena bombing may be delayed because of a delay in providing evidence by the police.
Greater Manchester Police have failed to provide statements more than two years after the terror attack, a hearing was told.
Fiona Barton QC, representing Greater Manchester Police (GMP) made a public apology for the delay to around 30 relatives of the victims present at the preliminary hearing of the Manchester Arena Inquiry.
Addressing the families at Manchester Town Hall, she said: "May I turn to the families and apologise profusely for the delay."
From across the room one relative responded: "Not accepted."
Elaine Wilcox has been at the hearing today:
Retired High Court judge Sir John Saunders, chairing the inquiry, said: "If there's delay and it is due to GMP I have no doubt there will be extremely extensive public criticism of GMP.
"What I'm absolutely insistent on is this inquiry has to start on April 6.
"It is simply not fair to the families or to anyone else or to Manchester in general."
Stephen Howe, whose wife Alison, 45, was among the 22 who died in the suicide attack, said GMP's response was "diabolical" as it was now more than two years since the bombing.
Suicide bomber Salman Abedi killed 22 people and injured hundreds more by detonating a rucksack bomb at the end of an Ariana Grande concert on May 22 2017.
The bomber's younger brother, Hashem Abedi, will go on trial in January denying 22 counts of murder.
The statements were requested from GMP as part of the inquests into the deaths of the 22 victims, examining the build-up and the attack itself, security at the arena, the emergency response and background to the atrocity including the actions of the police and security services.
The inquests were turned into a public inquiry in October so that secret evidence could be heard behind closed doors without the families of the victims and their lawyers being present as it was ruled public disclosure of the information would be a national security risk.
Paul Greaney QC, counsel to the Inquiry, told the hearing witness statements relating to command and control issues were first requested from 12 key individuals at GMP in April.
They were told to provide them in August, but only six have been given so far, those having been emailed last night.
Mr Greaney also said there was a second problem with "gaps" in the 550 hours of radio transmission recordings from the night of the bombing provided by GMP.
Peter Weatherby, representing some of the families, told the hearing: "This sorry tale Mr Greaney indicates is frankly not good enough."