SIR John Chilcot has said he does not believe Tony Blair was "straight with the nation" about his decisions in the run-up to the Iraq War.
In an interview with the BBC on the anniversary of his report into the 2003 conflict, Sir John said the former prime minister had been "emotionally truthful" in his account of events leading up to the conflict.
But he suggested Mr Blair – who once described himself as "a pretty straight sort of guy" – relied on "belief" rather than "fact".
Mr Blair's office accused the BBC of putting words in Sir John's mouth, and insisted that the full interview showed that the former Whitehall mandarin did not think he had "departed from the truth".
"The BBC headline stems from words put into John Chilcot's mouth by the interviewer," said a spokeswoman for the former prime minister.
"A full reading of the interview shows that Sir John makes clear that Mr Blair had not 'departed from the truth'.
"Sir John also makes clear that on the eve of the invasion Mr Blair, 'asked the then Chair of the Joint Intelligence Committee, can you tell me beyond any reasonable doubt that Saddam has weapons of mass destruction. To which the answer was, yes I can. He was entitled to rely on that'.
"Five different inquiries have all shown the same thing: that there was no falsifying of the intelligence."
Speaking to the BBC, the chair of the inquiry into the Iraq War was asked if Mr Blair was as truthful with him and the public as he should have been.
"Any prime minister taking a country into war has got to be straight with the nation and carry it, so far as possible, with him or her," he replied.
"I don't believe that was the case in the Iraq instance."
Released last year after seven years of investigation, the Chilcot Report found that former Iraqi dictator Saddam Hussein posed ''no imminent threat'' at the time of the invasion of his country in 2003 and the war was fought on the basis of "flawed" intelligence.
While giving evidence to the inquiry, Mr Blair denied he had taken the country to war on the basis of a "lie" over Saddam's supposed weapons of mass destruction.
Asked if he felt Mr Blair had given the fullest version of events to the inquiry, Sir John said: "I think he gave an - what was - I hesitate to say this, rather, but I think it was, from his perspective and standpoint, emotionally truthful and I think that came out also in his press conference after the launch statement.
"I think he was under - as you said just now - very great emotional pressure during those sessions ... He was suffering. He was deeply engaged. Now in that state of mind and mood you fall back on your instinctive skills and reactions, I think."
In a now infamous claim, Mr Blair told MPs that Saddam Hussein was developing weapons of mass destruction, and later said intelligence showed the Iraqi tyrant could deploy chemical and biological weapons within 45 minutes.
Sir John's report found Mr Blair presented the case for war with "a certainty which was not justified" based on "flawed" intelligence about the country's supposed weapons of mass destruction (WMD) which was not challenged as it should have been.
Asked if was "exaggerated", Sir John replied: "He found - I don't know whether consciously or not - a verbal formula in the dossier and his foreword to it.
"He said - and used it again later - 'I believe the assessed intelligence shows beyond doubt.' Pinning it on my belief, not on the fact, what the assessed intelligence said."
Referring to Mr Blair's appearance at the inquiry, Sir John said: "Tony Blair is always and ever an advocate.
"He makes the most persuasive case he can.
"Not departing from the truth but persuasion is everything. Advocacy for my position, my Blair position."
Asked if Mr Blair had manipulated the evidence, Sir John replied: "I'm declining the word 'manipulate'.
"Using as best he could.
"But it's only fair to him to say that on the very eve of the invasion he asked the then chair of the Joint Intelligence Committee, can you tell me beyond any reasonable doubt that Saddam has weapons of mass destruction.
"To which the answer was, yes I can.
"He was entitled to rely on that. But would it have been wise to rely on it?"
Lord (Menzies) Campbell, who opposed the war as foreign affairs spokesman of the Liberal Democrats during the run-up to military action, told the Press Association: "No-one should be surprised by Sir John Chilcot's analysis today.
"By reading between the lines of his report a year ago, it was always clear that he and his colleagues were deeply critical of Tony Blair's unequivocal commitment to George Bush's determination to take military action against Saddam Hussein in order to effect regime change.
"In truth, Mr Blair's decision was fundamentally wrong.
"A bad decision, even if made in good faith, is still a bad decision."
Foreign Secretary Boris Johnson said that "wittingly or unwittingly" the information about Iraq's weapons of mass destruction was not accurate.
At a press conference in London he said: "I remember very clearly there was an incredibly active public debate.
"Everybody was involved in it, certainly parliamentarians were involved in it and we all tried to take a view on the best information that we thought we had.
"Looking back on it we have to be realistic that and say that some of the information, wittingly or unwittingly, some of the information that emerged from government about weapons of mass destruction did not turn out to be accurate.
"It is there that we have to learn the lessons of the Chilcot report and I believe those lessons have been learned."
