When Gordon Brown asked Sir John Chilcot to head a commission to enquire into the Iraq war, few expected it to come up with anything earthshaking. Chilcot was widely seen as a “safe pair of hands”, and a pro-establishment mandarin who was not known to rock the boat.

And so it has proved to be: in a series of interviews with the principal actors in the run-up to the bloody but unnecessary war, no great revelations have emerged. The effect of being grilled by Chilcot has been likened to “being mauled by a toothless sheep”. Tony Blair was allowed to drone on for hours, expanding on all the reasons why he thought the war was a good idea. His misuse of intelligence was not seriously questioned by the commission, and he was permitted to leave scot free, with his loathsome grin in place.

Blair's powerful spin doctor Alastair Campbell was similarly let off the hook. This despite widespread charges in the media that he had been a key player who had used his proximity to Blair to bully the British intelligence community into sexing up the dodgy intelligence dossier that was used by Blair into persuading Parliament to authorise him to attack Iraq.

But now, after Chilcot had interviewed all the witnesses in the drama, a senior intelligence officer has claimed that Campbell lied in his testimony. Major General Michael Laurie, director general of the Defence Intelligence Staff, responsible for collating and analysing raw intelligence data before the Iraq war, has delivered a bombshell that has produced a gaping hole in the Blair-Campbell narrative.

Quoted in the Guardian, Laurie said to the commission: “I am writing to comment on the position taken by Alastair Campbell during his evidence to you… when he stated that the purpose of the dossier was not to make a case for war; I and those involved in its production saw it exactly as that, and that was the direction we were given…

“Alastair Campbell said to the enquiry that the purpose of the dossier was not to 'make a case for war'. I had no doubt at the time this was exactly its purpose and these very words wer used…

“We knew at the time that the purpose of the dossier was precisely to make a case for war, rather than setting out the available intelligence, and that to make the best out of sparse and inconclusive intelligence the wording was developed with care.“We could find no evidence of planes, missiles or equipment that related to WMD, generally concluding that they must have been dismantled, buried or taken abroad. There has probably never been a greater detailed scrutiny of any piece of ground in any country.”While this statement is damning evidence of the lack of any solid information about Iraqi WMDs, the Chilcot enquiry has also released other secret documents that it has received. Some relate to MI6 (the British Secret Service) warnings that if the UK did indeed join the US in attacking Iraq, it would become more vulnerable to terrorist attacks.

However, a declassified document also contains a warning from a senior official warning Geoff Hoon, the defence secretary, of the harm it would do to Britain's famous special relationship with the US if it did not join its American ally in attacking Iraq. And despite its reservations, MI6 did tell ministers before the invasion that toppling Saddam Hussein “remains a prize because it could give new security to oil supplies.”

After Laurie's devastating evidence emerged, there were immediate calls for Chilcot to summon Campbell for further questioning. Several MPs have joined this chorus, but it is unlikely to happen as the commission is now writing its report, and to collect and evaluate further testimony at this point would delay its findings. Campbell himself, when contacted by the media, said he had “nothing to add” to his earlier testimony.

Bloggers on the Evening Standard were very caustic. Said one:

“There is little point in singling out that depraved man Campbell. The whole Labour government was rotten to the core – deceitful, dishonest and fiscally incompetent…”

Wrote another: “I never cease to be amazed that this man (Campbell) was given all the power, authority and access to high places and people that he did clearly have… A 'nobody' plucked from the depths of obscure journalism and elevated by a Prime Minister who was himself an utter disgrace to a position where he helped influence, advise and dictate the major issues affecting this country. All who had a hand in deciding the case for war should be tried for war crimes, Campbell included.”

Here's short, pithy blog: “The man's arrogant, conceited and as full of s**t as his old boss. I wouldn't believe him if he told me Sunday comes before Monday.”

These comments give some sense of the respect Blair and Campbell command, even among Labour supporters. They will have to live with the toxic fallout from the Iraq war for the rest of their lives. When Blair's memoirs were published last year, he was unable to go to book-signing events organised by his publisher because of the hostile crowds that gathered wherever he was due to make an appearance. His book was surreptitiously moved from the 'autobiography' section of bookshops to the area reserved for crime stories.

When it became crystal clear that there were indeed no WMDs in Iraq, and the British forces had been sent to war on false pretexts, the fury among my English friends was palpable. They could not believe they, the media and Parliament had been so easily duped by Blair and his inner circle.

I reassured them by saying that in my experience, politicians lied all the time. In fact, duplicity was practically a job requirement for them. After a while, spinning the truth became a default position, and lies tripped easily from their forked tongues. More than ever, the old slogan “Bliar Blair” rings true.