Over the years, I have written a fair number of pieces about Alastair Campbell, Tony Blair's spin doctor.

I'm not his greatest fan. I believe he was a malign influence on British public life, particularly in relation to the Iraq war.

But until now I had assumed that Mr Campbell was essentially a rough-and-tumble former red-top tabloid journalist and bully who had a loose relationship with the truth.

Former spin doctor Alastair Campbell, left, refuses to accept any blame for himself or then Prime Minister Tony Blair for Britain's entry into the Iraq War

How often I have quoted the words of Mr Justice Drake, who in a 1996 court case questioned the veracity of the future Torquemada of No 10.

What happened on Tuesday altered my perception.

I don't doubt that, as in previous inquiries into the war, he twisted the truth a good deal in his 'evidence'.

But it dawned on me that he is no mere casual liar who calculatingly and cynically tells fibs.

He passionately believes in one cause - Tony Blair and the Iraq war - and, just as he was prepared to refashion reality when he and his master made the case for war, so he is happy to do so again nearly seven years later.

Anyone who disagrees with him is vilified: previous witnesses at the Chilcot Inquiry, such as Sir Christopher Meyer, former Ambassador to Washington, described as 'not accurate,' 'churlish' and 'glib'; the
French, attacked several times because they had 'pulled the plug' on a
UN resolution authorising force; the BBC, which had the temerity to
allege he had 'sexed up' the case for war; and, of course, nearly all
journalists, a group he thinks are mendacious, superficial or both.

During a break on Tuesday, he wrote on his Twitter page: 'Watching lunchtime news. God these hacks do talk some drivel.'

He wrote in his blog that he would give the next day's newspapers 'a miss'. I suppose they might challenge his version of reality.

It is Alastair Campbell, Tony Blair and a diminishing band of like-minded souls against the rest of the world, which is peopled by charlatans, liars and fools.

He even represents himself in his blog as a kind of virtuous Old Testament prophet entering a den of iniquity - the inquiry - and, though an avowed atheist, quotes from Psalm 56: 'What can mortal man do to me?

'All day long they twist my words, they are always plotting to harm me. They conspire, they lurk, they watch my steps, eager to take my life.'

This portentous self-dramatisation is very odd. A psychiatrist might discern symptoms of a persecution complex.

It is striking that Mr Campbell accuses his critics of the very faults with which he himself is so lavishly endowed.

What is true of his blog applies to his performance on Tuesday. On the face of it, he held up well during nearly five hours of questioning. (His blog makes clear the incredibly elaborate preparations he undertook.)

Throughout it all, he remained suave, self-controlled and apparently reasonable. Many commentators complimented him.

Few remarked that under this polished veneer there ran a persistent undercurrent of self-delusion that can only be described as barking.

At one point, when discussing the Government's September 2002 dossier - which alleged that Saddam Hussein possessed weapons of mass destruction (WMD) - Mr Campbell said: 'I defend every single word of the dossier. I defend every single word of the process.'

How can this be? The dossier was utterly mistaken in supposing that Iraq had WMD.

Mr Campbell might have said there were some sound reasons then for thinking that it did, but now he accepted he had been wrong. Instead he stands by every word of a discredited document.

This is a perfect example of Mr Campbell's amazing propensity to disregard reality - as pronounced now as it was in September 2002.

Equally, he could not get his head around the idea that Mr Blair went considerably further than the intelligence justified when he wrote in the introduction to the same dossier that it was 'beyond doubt' that Iraq possessed WMD.

'Denial' is the word usually employed to describe a person's reluctance or inability to face facts. Mr Campbell has it in spades.

So he can toss off the disclosure that Tony Blair sent President George W. Bush a number of letters in 2002 in which he made it clear that, if it came to it, Britain would be ready to stand by the U.S. militarily.

Only he and Jack Straw, the then Foreign Secretary, were aware of what Mr Blair was doing.

Without reference to the Cabinet, let alone Parliament - and at a time when the Attorney General was advising that 'regime change' would not offer a legal pretext for invasion - Tony Blair was giving private assurances of military action to the U.S. President.

Perhaps because Mr Campbell himself was so unfazed by his revelation, many of the commentators have not woken up to how shocking it is.

It is a constitutional outrage, a case of 'sofa government' gone mad, that Blair, Campbell and Straw should have put the Armed Forces of this country secretly at the disposal of a foreign power.

It is a sign of how far removed Mr Campbell is from reality - which, in this case, means the proper observance of constitutional conventions - that he should have made this disclosure so lightly and without any sense of the gross impropriety involved.

Even he subsequently appears to have thought he might have gone too far.

In his blog, he claims that on page 684 of his autobiography he had already referred to Mr Blair's notes to Mr Bush.

A close reading shows this is another characteristic exaggeration since his book does not mention any military undertaking to the U.S. President.

Interestingly, Mr Campbell was also asked on Tuesday about the February 2003 dossier, which was a farrago of invention and plagiarism, though this did not prevent it being cited admiringly by Colin Powell, the then U.S. Secretary of State.

Even Mr Campbell could not sanitise this abomination, but brushed it aside as a 'mistake'. For this deception alone the man should have been drummed out of British public life.

Tony Blair will give evidence to the Chilcot Inquiry at the end of the month.

Doubtless, the former leader of what resembles a tiny and discredited cult will give a performance as polished and, on the surface, as sane as his former sidekick.

He, too, will be treated with respect. But will he show any greater apprehension