Sir John Chilcot, who is Chairing the six-year investigation, will instead appropriate a higher proportion of criticism to ministers who served under the Prime Minister in 2003 than previously expected, Guardian journalists claim.
Those tipped to be under fire could include former foreign secretary Jack Straw, ex-head of MI6 Sir Richard Dearlove, and Clare Short, then international development minister.
Others in focus, the Guardian says, are Sir John Scarlett, chairman of the joint intelligence committee, Geoff Hoon, the defence secretary, and officials from two government departments.
Each person criticised by Chilcot and his four co-committee members will have to be sent draft passages of their comments, allowing them an opportunity to comment.
But this process, which has already been delayed multiple times, could drag on even further if a wider pool of people are being waited on to respond.
It originally suffered a three-year hold-up because of a dispute between Chilcot and successive cabinet secretaries over which minutes of conversations between Tony Blair and ex-US President George W Bush could be published.
The report's publication date has been repeatedly put back even further, as its Chair insists his team need more time to allow for replies from figures criticised, even though hearings were completed back in 2011 -- the ensuing process has cost taxpayers more than £10 million to date.
David Cameron last week put pressure on Chilcot to finally deliver his findings, commenting: “It’s frustrating. We want this inquiry finished. It’s for the good of the families. It’s for the good of the country.”