British soldiers have been in Iraq since the US-led invasion in 2003
A full public inquiry into the decision to invade Iraq is needed because "a lot of facts still have to come to light", a former diplomat has told MPs.
Carne Ross said it was "disgraceful" of ministers to "pretend" the Butler and Hutton inquiries told the full story.
Mr Ross quit the Foreign Office over the accuracy of intelligence about Saddam's weapons.
He was giving evidence to a Public Administration Committee inquiry into civil service leaks and whistleblowers.
Mr Ross, who was Britain's leading expert on Iraq at the United Nations for four years before the war, quit his job after giving secret evidence to the 2004 Butler inquiry into the use of intelligence.
'Many other people'
He told MPs: "I feel very strongly that there has still not been proper accountability over what happened in Iraq.
"There should be a full public inquiry, or Parliamentary inquiry, into the decision-making that took place.
"Hutton and Butler are by no means sufficient for that purpose and it is disgraceful that the government pretends that they are. It is disgraceful.
"A lot of decision-making, a lot of facts have still to come to light in the run up to this war, which should come to light, which the public deserves to know."
Asked what this information was, he said he was "happy" to let his evidence to the Butler inquiry "stand as my view".
But he added: "There are many other people involved who have yet to tell their story, who have yet to be questioned by Parliament or anybody else."
The culture of Whitehall leaks that has sprung up in recent years had been caused by a "fundamental failure of transparency and accountability in government", he added.
There were fresh calls for an inquiry last week after the release under Freedom of Information laws of a Downing Street memo showing that intelligence chiefs were urged to make a key dossier on the Iraqi threat as "firm" as possible.
And in February Justice Secretary Jack Straw vetoed the publication of minutes of cabinet meetings discussing the legality of the war in the run-up to the invasion.
Former senior defence intelligence expert Brian Jones also made the case for an inquiry into the war, claiming nothing had changed as a result of the Hutton and Butler probes.
He told MPs: "Having seen all that has happened since the Iraq war and the evidence that has come from the various inquiries, beyond a very small group of MPs who have, as it were, seen through some of the nonsense, for someone like me it has been very disappointing."
Mr Jones, a former colleague of Dr David Kelly, became a whistleblower in 2004 when he said intelligence chiefs ignored warnings from their own experts that they could not be certain Iraq had chemical and biological weapons.
He told MPs he had formally complained about a dossier on Saddam's alleged weapons as he feared the intelligence community would be "crucified" after its publication.
He said he was "surprised" that MPs did not spot its flaws by themselves, telling the committee: "I don't think it needed someone of my expertise to look at the dossier and see the difference between the prime minister's foreword and what was in the main body of the dossier."
He had not considered quitting his job to go public with his concerns or contacting MPs, he said, who, with a few exceptions, had been "misled" on Iraq by ministers. He retired in January 2003.
Katherine Gun, a whistleblower who was sacked from her translator's job at secret listening post GCHQ, told MPs she got a "very big shock" when she saw an e-mail from the US National Security Agency in January 2003.
The e-mail asked for British help to spy on the six countries whose support was needed to win a UN Security Council Resolution authorising the invasion of Iraq, she said.
"What we were being asked to do was politicise intelligence and we subsequently found out, thanks to the leaking of the Downing Street memo, that policy was being fixed around intelligence".
She said she felt she had no alternative but to go to the media with her concerns.
If she had raised it with her managers their reaction would have been to "sweep it under the carpet" and put her on top of the "watch list of most dangerous persons in the organisation".
She added: "Working on the inside, there are people whose views are similar to my own but they dare not speak their mind and wish to keep their jobs which I perfectly understand but the vast majority of people have group think" and "dare not think outside the boundaries."
Mrs Gun confessed to leaking the e-mail and was charged with breaking the Official Secrets Act but the case was later dropped because, she claimed, if she had won it would have "set a precedent".
She called for a change in the training of spies who were constantly told of the consequences of breaking the Official Secrets Act but not told what to do if they had moral concerns about their work.
Former Foreign Office official Derek Pasquill, attacked the "patronising" attitude of senior managers who tended to say "leave this to us" when concerns were raised.
He said the concerns he raised in 2005 - about what he claimed amounted to government-sponsored "radicalisation" of Muslim youths - was still relevant, although some government departments now took a different approach.
Mr Pasquill was accused of breaching the Official Secrets Act but was cleared in January last year after prosecutors dropped the charges.