The Northern Ireland Secretary of State Owen Paterson has received a copy of the Saville inquiry report into the events of Bloody Sunday, in Derry in 1972.
The families of those killed and injured, the soldiers involved and some MPs will get access to the report tomorrow, shortly before it is published.
The inquiry was set up to re-examine the deaths of 13 people killed when British soldiers opened fire on a civil rights march.
Relatives of those killed on Bloody Sunday were tonight expecting the names of all those killed on the day to be cleared by the long-awaited report.
Families of the victims will form a silent procession in the morning from Derry's Bogside along the intended route of the original march to the city's Guildhall where the findings will be published.
Two relatives of each of those killed and injured will be given advance access under strict security arrangements.
Mickey McKinney, whose 27-year-old brother Willie was shot dead on the day, said families of victims and others were tense as they prepared for the findings.
"I think people are becoming very anxious, I think they're getting a bit nervous," he said.
"It's been a long time but it's here now and we just want to see it." Mr McKinney said he remained hopeful about the outcome but insisted he and others cannot move on unless people are held to account for the shootings.
"We want the truth - a declaration of innocence and a recommendation that those responsible are prosecuted," he said.
"I think the worst-case scenario would be that \[Lord Saville] wouldn't leave the blame with the Parachute Regiment and the [British] government, but I don't think that will happen.
"People should be held to account, that's what must happen." The full report, expected to contain 5,000 pages and which runs to 10 volumes, will be fully published at 3.30pm as prime minister David Cameron makes a statement in the House of Commons.
A large screen has been erected in the Guildhall Square to relay the statement to those gathered.
Set up in 1998, Lord Saville's re-examination of how 14 people died as the British Army opened fire on a civil rights march is the longest and most expensive public inquiry in British history.
A controversial inquiry by then Lord Chief Justice John Widgery, published on April 19th, 1972, effectively absolved the soldiers of any blame and claimed many of the dead had been armed.
This report has long been considered a complete whitewash by the victims' families.
A subsequent campaign, alongside political developments in the peace process and pressure from the Irish Government, eventually led then prime minister Tony Blair to order the inquiry.
Mr McKinney said if justice is done after the publication of the report, then people will finally move on from one of the most pivotal and enduring events in Northern Ireland.
"That's why we campaigned all those years, because our people were murdered and the state and its employees covered it up and told lies," he said.
"The truth must be told and the blame must be left at the doorstep of the state and the British army.
"If I know justice has been done I'll be able to move on and know I did my best." Sitting in the Guildhall, Derry, and Central Hall at Westminster in London, to accommodate military witnesses, the inquiry has cost £190.3 million (sterling) up to February 2010.
Around 2,500 people gave testimony, with 922 of these called to give oral evidence, including 505 civilians, nine experts and forensic scientists, 49 journalists, 245 military, 35 paramilitaries or former paramilitaries, 39 politicians and civil servants, seven priests and 33 Royal Ulster Constabulary officers.
Evidence ran to 160 volumes of data with an estimated 30 million words, 13 volumes of photographs, 121 audio tapes and 10 video tapes.
PA