The families of the 96 people who died in the Hillsborough disaster will receive a report on Wednesday intended to establish the truth about what happened that day and in the aftermath, based on an examination of thousands of official papers.
David Cameron will make a statement in the House of Commons on the report, expected at about 12.30pm after prime minister's questions. He has been urged by the families and Merseyside Labour MPs to deliver an apology over failures that caused the disaster, and over the attempt by South Yorkshire police to shift blame on to Liverpool supporters.
The report by the Hillsborough independent panel, established three years ago and chaired by the bishop of Liverpool, James Jones, will be accompanied by the publication later on Wednesday of 400,000 official documents from 80 organisations. The families of victims will be shown the documents before they are publicly released.
The families have for 23 years held a burning sense of injustice that those who died at the FA Cup semi-final between Liverpool and Nottingham Forest on 15 April 1989 were failed by the legal processes that followed.
In the aftermath of the deaths of Liverpool fans in the central "pens" of the Leppings Lane terrace, South Yorkshire police claimed that the disaster had been caused by drunk and misbehaving supporters, many without tickets, forming a crush outside Sheffield Wednesday's football ground.
Four months later, the official report by Lord Justice Taylor dismissed those claims emphatically and criticised the police for advancing them. Taylor judged that the police's own mismanagement of the crowd had been the prime cause of the disaster, together with serious safety deficiencies at the stadium itself and Sheffield city council's failure to oversee safety.
However, at the inquest into the deaths the police repeated their effort to blame the disaster on supporters. It later emerged that the police had mounted an internal corporate operation to change the statements of junior officers to reflect that claim, remove criticism of the force and stress any stories of supporters misbehaving. Nobody in authority has ever resigned, been prosecuted, disciplined or taken official responsibility for the failures that led to the disaster or what the families describe as the cover-up that followed.
At the inquest, the coroner, Dr Stefan Popper, imposed a cut-off of 3.15pm on the day of the disaster beyond which he heard no evidence, ruling that all the victims had received their fatal injuries by then. That meant the families have never discovered precisely how their relatives died, and that the ambulance response and any efforts to attend to the dying have never been examined.
The process of disclosing internal papers was prompted by Labour's then ministers Andy Burnham and Maria Eagle in 2009. The panel of experts was set up to interpret the documents and produce a report on how the disclosures "add to the public understanding" of the disaster. The Conservative-Liberal Democrat government committed to continuing the process when it came into office in 2010.
The chair of the Hillsborough Family Support Group, Margaret Aspinall, has said the families now want the full truth to be set out by the panel's report. She argues that if the families' case is vindicated – that fans were not to blame and the police and other bodies were culpable – the inquest verdict of accidental death should be set aside.
Aspinall, whose son James died in the disaster, said: "Without the truth you cannot grieve and where there is deceit, you get no justice."
She told BBC Breakfast: "After 23 years fighting for the truth, fighting for
accountability - and I think that is very important - I think it is
very important to say that we do want accountability for 96 lives."
Trevor Hicks, whose daughters Vicki, 15, and Sarah, 19, died in the
disaster said: "We are not asking for any more than we should have been
given without having to fight long and hard for it."
Hicks, a former chairman of the support group, told BBC's Today programme that the decision of the coroner to impose a 3.15pm cut-off "was a perfectly legal decision but it wasn't a moral one".
He hoped the report would change "this sense of injustice" felt by the families of those who died. "The unknown is more difficult to cope with than the known."