The relatives of some of the 179 Britons killed in the Iraq war plan to boycott the long-awaited Chilcot inquiry report into the conflict as they fear it will be a "whitewash".
The two million-word report, six years in the making, will be unveiled by Sir John Chilcot on Thursday (NZT).
Tony Blair, prime minister when Britain went to war, has said he will not make any comment until the report is made public.
The International Criminal Court (ICC) has indicated the former Labour leader will not be liable for prosecution, reiterating its conclusion 10 years ago that the decision to go to war is not within its jurisdiction.
The court said it will look at the report's findings before deciding whether there is a "reasonable basis" to begin an investigation.
Speaking to Sky News on Sunday Mr Blair said: "I have taken the view, I think rightly or wrongly, we should wait for the report to be published and then I will express myself and I'm not getting into either the politics or the detail of it until I've actually seen it."
A number of MPs are expected to try to use an ancient law to try to impeach the former prime minister once the findings are published.
Former Scottish First Minister Alex Salmond said there "has to be a judicial or political reckoning" for Blair's role in the Iraq conflict while shadow chancellor John McDonnell said the "processes" of how Britain ended up at war must be examined "so we never ever get into this tragic, tragic mess again with such loss of life".
Some of those whose loved ones died in the war between 2003 and 2009 fear the report will not give them the answers they desperately want.
Gary Nicholson, 42, was one of 10 servicemen who died when their Hercules C-130 aircraft was shot down in 2005.
His mother Julia said: "It will be a whitewash. I'm absolutely disgusted. I'm not going because it will be a whitewash.
"Tony Blair has got blood on his hands. He will have covered his back and (George) Bush's back."
The Chilcot inquiry was set up in 2009 by then prime minister Gordon Brown after the withdrawal of the main body of British troops earlier that year.
The inquiry examined the lead up to the 2003 invasion, and the years up to the 2009 withdrawal.
The report's long-awaited publication follows 130 sessions of oral evidence and the testimony of more than 150 witnesses.
The inquiry has analysed more than 150,000 government documents as well as other material related to the invasion.
Relatives of the service personnel killed in Iraq between 2003 and 2009 will get an early sight of a 150-page summary.
David Godfrey, whose grandson Daniel Coffey, 21, was killed in 2007, said: "I'm quite apprehensive at the moment.
"People say this should bring closure but it won't. It might give us information but what we need is closure.
"It can't bring anybody back and won't stop us feeling what we feel. It's just another step forward on another long journey."
He branded Mr Blair a "war criminal" and said "he has to be held responsible".