Relatives of the 96 Liverpool fans who died at Hillsborough have begun to examine thousands of previously unseen documents about the 1989 FA Cup semi-final disaster.
The Hillsborough Independent Panel has been assessing more than 400,000 pages of documents over the last year and a half, with the report of its findings also available for the families to view at Liverpool's Anglican Cathedral.
Documentation examined by the panel, chaired by the Right Reverend James Jones, Bishop of Liverpool, came from more than 80 different organisations. The documents, which will be released to the public on Wednesday afternoon, were available to the relatives from 8am.
The report and the release of the documents follow more than two decades of campaigning by the families of those who died on the terraces at the Leppings Lane end as they went to watch their team play Nottingham Forest at Sheffield Wednesday's ground 23 years ago.
MPs agreed to the disclosure of Cabinet papers last year - a move breaking with the convention that such papers are not usually published until 30 years after they are written.
Permission for their release came after a House of Commons debate triggered when 140,000 people signed a government e-petition set up by Brian Irvine, a Liverpool fan.
After the tragedy - Britain's worst sporting disaster - Lord Chief Justice Taylor led an independent inquiry which concluded that the main cause of the fatal crush had been a lack of crowd control by South Yorkshire police. The Crown Prosecution Service ruled that there was insufficient evidence to bring a prosecution.
The papers being released on Wednesday are expected to reveal more about how events unfolded, their aftermath and the response of Margaret Thatcher's Conservative government.
Margaret Aspinall, the chair of the Hillsborough Families Support Group, said: "This is what the families and the fans have been fighting for for 23 years. Without the truth, you cannot grieve, and where there is deceit, you get no justice.''
The families say it is an injustice that no individual or organisation has ever been held fully accountable for the disaster. They say South Yorkshire Police never initiated a major incident plan, and that those in the Leppings Lane end did not get emergency medical attention.
Many feel a cover-up was organised to deflect blame from the police on to the Liverpool supporters. In the aftermath, the South Yorkshire force claimed the disaster had been caused by drunk supporters, many without tickets, forming a crush outside the ground.
Four months later, the Taylor report dismissed those claims and criticised the police for putting them forward. At the inquest into the deaths, police repeated their effort to blame the disaster on supporters.
The 1991 inquest ruled that all the victims had died 15 minutes after the game began at 3pm - but this is disputed by relatives, who want to know whether more lives could have been saved. Many would like to see a new inquest opened because the original refused to hear evidence from after 3.15pm.
The government has said the Attorney General has agreed to determine whether the evidence available supports an application for a new inquest.
At noon, a ministerial statement will be read out from London, and will be followed by a press conference at Liverpool Cathedral. The prime minister, David Cameron, will make a statement to the Commons.
A two-minute silence will be held in Liverpool at 3.06pm - the exact moment the semi-final was stopped as the scale of the disaster that was unfolding became apparent.
Sheffield Wednesday have offered an apology to the relatives of those killed at the club's ground and said they hoped the release of the documents would "bring closure''.