Sir John Chilcot, the chairman of the inquiry into the Iraq war, provokes controversy after saying his report will not be published until after the May election – six years after he began his work.
After the Hutton and Butler inquiries, there were unanswered questions about the build-up to the Iraq war, how it was waged and what went wrong afterwards.
There were lessons to be learned, following the deaths of tens of thousands of Iraqi civilians during the early years of the occupation, when US and British troops failed to establish order, counter the insurgency and stem the bloodshed.
Hence Gordon Brown’s decision to order another inquiry.
Sir John has been looking at why the UK went to war in 2003, whether it was legal, what happened after Saddan Hussein was toppled, and whether the British people were misled about Iraqi weapons of mass destruction, which were never found.
The inquiry was set up by Gordon Brown in 2009 and heard from its last witness in 2011. More than 100 people appeared before it.
Inquiries do not come cheap: this one has cost £9m.
There was wrangling over how much of Tony Blair’s correspondence with George Bush should be released.
Then there was the issue of “Maxwellisation”, where people criticised in the report are given an opportunity to respond, along with the need to declassify thousands of official papers.
In his letter to the prime minister, Sir John says “individuals are currently being given the opportunity to respond to provisional criticism of them in the inquiry’s draft report”.
He adds: “Until we have received and evaluated responses from all those who have been given the opportunity to respond, I cannot give an accurate estimate for how long it will then take to complete our work, but it is clear that will take some further months. I therefore see no realistic prospect of delivering our report to you before the general election in May 2015.”
Critics of the Iraq war suspect that, months before the invasion, Mr Blair gave President Bush assurances that the UK would take part, while he was telling the British people that no decisions had been taken.
Although Cabinet Secretary Sir Jeremy Heywood blocked publication of the full exchanges between the two leaders, Sir John has previously said the “gist” would be released.
Sir John now says in his letter to David Cameron that 29 of Mr Blair’s “notes” to the former president will be published, “subject to a very small number of essential redaction”.
In his defence, Tony Blair denies he has delayed publication and says he wants the report published as soon as possible.
When he appeared before Chilcot, he robustly defended the invasion, saying he had not struck a secret deal with President Bush and had believed Saddam Hussein had weapons of mass destruction.
Writing to Sir John, the prime minister says he would have liked the report to have been published “well before the forthcoming election”, but he accepts “it will not now be possible for you to submit your final report to the government and parliament until after the election”.
Mr Cameron knows that Labour has more to fear from the Chilcot report than the other parties because it was Tony Blair’s government that took Britain to war – albeit with the support of the Conservative opposition.
The deputy prime minister and Liberal Democrat leader has also written to Sir John saying: “If the findings are not published with a sense of immediacy, there is a real danger the public will assume the report is being ‘sexed down’ by individuals rebutting criticisms put to them by the inquiry, whether that is the case or not.”
The use of the expression “sexed down” is a reference to claims that a 2002 dossier on Iraq’s weapons of mass destruction had been “sexed up” to justify military action.
When weapons were not found following the invasion – and tens of thousands of Iraqi civilians were killed in the violence that enveloped the country after Saddam Hussein was overthrown – Messrs Blair and Bush were accused of starting the war on a false premise.
Unlike David Cameron’s party, the Lib Dems opposed the war.