Every dot and comma and the 2m words of evidence between them will be forensically examined to ensure report cannot be undermined

First, we were told it would be ready sometime in 2011, then the next year, then the next. Now we are told the Chilcot inquiry will be completed by April, but will not be published until June or July, seven years after Gordon Brown’s announcement that it was to be set up – longer than British soldiers spent occupying Iraq, fighting and trying to keep the peace in an increasingly violent and sectarian civil war.

Why? The answer is that Sir John Chilcot and his three colleagues are worried that if their criticisms of individuals, from Tony Blair downwards, are not bolted down by oral, and more importantly written, evidence, their report will be undermined.

Chilcot report to be published next summer after security checking Read more

They will forensically examine every dot and comma, and the more than 2m words between them, to ensure that those they criticise – and they should be many – will not be able to answer back. Some, including, it is believed, Jack Straw, foreign secretary at the time of the ill-fated invasion of Iraq, have been consulting lawyers. Others, including, it is believed, Sir Richard Dearlove, then head of MI6, have already drawn up a rebuttal. Not exactly getting their retaliation in first – though Blair has tried to do this in a half-hearted way – but ready to pounce.

The Chilcot report was delayed first because of arguments with successive cabinet secretaries – Gus O’Donnell and Jeremy Heywood – over which of the secret and sensitive documents the inquiry had been given could be published. Notable among these were notes of conversations between Blair and George Bush in the years and months leading up to the invasion of Iraq in March 2003.

Chilcot and his team did not want to send draft passages to those in the firing line – in the so-called Maxwellisation process – until he knew what could be published. This was to ensure that the criticisms could be backed up by published evidence for all to see.

But then Chilcot himself was undermined. It became clear, as the Maxwellisation process got under way, that Whitehall had held back relevant documents from the inquiry only to give them later to those the inquiry planned to criticise. This has caused further delays, and aggravated the deteriorating relations between Chilcot on the one hand, and Whitehall, backed by 10 Downing Street, on the other.

Chilcot report likely to cast net of criticism far and wide Read more

For it also should be remembered that it is not only Blair and former Labour ministers and political advisers who will be attacked, but senior Whitehall officials – sometimes called the permanent government. Armed with a powerful weapon – the final say over what documents could and could not be published – they have fought a rearguard action against Chilcot.

And Whitehall has not yet finished, Chilcot made clear in his statement on Thursday. After the report is completed “confidential access will be given to a team of officials for national security checking”. Chilcot told David Cameron: “I entirely understand that a checking process is necessary and is normal procedure in inquiries which have considered a large volume of sensitive material.” But, as Chilcot must know full well, the phrase “national security” covers a multitude of sins.

The report should provide an unprecedented insight into one of the most disastrous decisions made by a British government in recent times – certainly since the 1956 Suez crisis. But it should do more than that. It should also provide unprecedented insights into the relations between military commanders and their political masters, how Britain was governed, and how it should not be ever again. Whether the long delay should have raised our expectations or lowered them, we will have to wait for another seven months to find out.