By Nick Assinder BBC News Online political correspondent at the Hutton inquiry

Alastair Campbell's diaries were always going to be a star exhibit at the Hutton inquiry.

And the extracts of this volume flashed up on the monitor screen during his second appearance certainly lived up to expectations.

There were entries showing just how eager Tony Blair's former spin chief was to reveal that an official had come forward as a possible source for Andrew Gilligan's controversial report on the claimed "sexing up" of the Iraq dossier.

The defence secretary had come out of his corner with his fists up.

One spoke of his desire to "get up" the source - to reveal his existence to the press - a move that was resisted by others, particularly Tony Blair.

Another revealed that defence chiefs "did not want to do it."

"Do what?" asked Lord Hutton - to which he never got a precise answer other than "putting it into the public domain".

And there was one particular entry that betrayed Mr Campbell's feelings at the time of the Gilligan report.

Written after Dr Kelly had come forward, but had yet to be named, it said that he and Mr Hoon had agreed that, if this was the source, it would "fuck Gilligan".

Strategy sanction

Other entries suggested it was the Ministry of Defence, not Downing Street, which had been in the lead in the process which ultimately led to the naming of Dr Kelly.

Mr Hoon will not have liked that one. Just a couple of hours before he had been telling the inquiry the go ahead for the strategy had come from No 10.

The defence secretary, widely viewed as the most likely government victim of this affair, had come out of his corner with his fists up.

However, he did finally accept he had sanctioned the process which ultimately led to the naming of Dr Kelly.

But it was the spin doctor in chief whose testimony was most eagerly awaited.

And you could see the asking price for Mr Campbell's memoirs - should he ever write them - skyrocketing.

Deconstruction exercise

It all gave the most graphic impression possible of the atmosphere of part frenzy, part fury that gripped Downing Street and Whitehall as the crisis developed.

Central to Mr Campbell's cross examination was Mr Gilligan's suggestion that the Iraq dossier had been sexed up.

That led to a gripping deconstruction of exactly what certain words meant when Mr Campbell had used them while offering advice to the man preparing the dossier.

According to Mr Campbell, his calls for the document to be "strengthened " did not mean "sexed up."

It meant the dossier should be a "good, solid piece of work" which the prime minister could present to parliament and the wider world.

When he had noted that the text of the dossier claimed Saddam "may" be able to launch weapons within 45 minutes, while the summary said "could" , he had merely been pointing out an inconsistency. Not suggesting which of the two he would prefer.

The thrust of the cross examination was that:

• A: Mr Campbell had indeed "sexed up" or "strengthened" the dossier - although Mr Gilligan's suggestions he had personally transformed the document by adding the 45 minute claim appear to have fallen by the wayside.

• B: That he was so desperate to defeat the BBC he was determined to get Dr Kelly's name into the newspapers as soon as possible.

Mr Campbell robustly dismissed both suggestions. And he never looked anything other than totally confident with his answers.

Fall guy?

Mr Hoon had previously given a similarly robust performance, showing that he has probably decided it is better to die on his feet than live on his knees.

The man long seen as the most likely government victim of the Kelly affair still has the look of a fall guy.

But he is clearly not as reconciled to that fate as it may sometimes have appeared in the past.

In some of the most ill-tempered exchanges yet seen at the Hutton inquiry, he constantly challenged claims about his role in the affair - notably the naming of David Kelly.

But he also confessed that he had sanctioned the process that ultimately led to Dr Kelly being named.

He also later admitted he did nothing to correct newspaper reports claiming the government's dossier on Iraq's ability to deploy weapons of mass destruction within 45 minutes referred to strategic weapons, not battlefield ones.

Mr Hoon was defiant and even aggressive. There was no conspiracy and he had done everything possible to protect Dr Kelly, he insisted.

Whether he is protected from the fallout from this affair remains to be seen.