What are the country's top political commentators making of the resignation of Alastair Campbell, the prime minister's director of communications and himself a former Fleet Street reporter?
Michael White, political editor, The Guardian
"I knew before I went on holiday that he might go and I think his main motive has been to go the day before I get back to the office. Typical Alastair.
"But seriously, I think he waited until after his evidence and that of Tony Blair's and Sir John Scarlett, the head of the intelligence committee, at the Hutton Inquiry.
"He would have probably gone earlier if it had not been for this because he has been on the way out since the last election.
In these kinds of jobs you wear yourself out physically.
"On top of that, the iron law is that when the spin doctor becomes as well known as the boss then it's time to move on.
"He can be very dogmatic. The political correspondent Peter Oborne describes him in his book as an Alpha Male - tall fair-haired and handsome and he could certainly shoot his mouth off when he needed to.
"He could be a bully - but you can't survive five minutes in that job without sometimes being a bully.
"He can be very charming when he wants to. When the late Tory MP and diarist Alan Clarke met him, he was quickly talking about him like he was his oldest friend. He once went around to supper at Campbell's - can you imagine that, an old-Etonian Tory MP?"
Toby Helm, political correspondent, Daily Telegraph
"I think it was widely expected that he was going to go - but I don't think anyone imagined that he would go on the day after the prime minister gave his evidence to the Hutton Inquiry.
"Why now, that remains somewhat mysterious. My initial thoughts would be that it looks like he has gone before he was pushed.
"But his resignation leaves Tony Blair with a huge gap by his side.
"Alastair Campbell has been there physically and intellectually for the last decade and even before during the formation of New Labour.
"It is very difficult to see how the prime minister can quickly get used to not having Alastair Campbell by his side."
Julia Langdon, political commentator and formerly Alastair Campbell's boss at the Daily Mirror
"The crucial question is timing. Why has he resigned today, the day after the prime minister has given evidence to the Hutton Inquiry.
"He did not have to go today. Tomorrow's papers would have been full of more analysis of the prime minister's performance and we have already had one very bad poll for him.
"Instead, the papers will now be full of stories about Alastair. He has made himself a lightning conductor, deflecting the attention away from Tony Blair. He has performed brilliantly.
"You might call me cynical for that, but I have known Alastair for 20 years. He is a supreme operator and propagandist."
Michael Cockerell, documentary maker who got exclusive access to Alastair Campbell at work
"It seems to me that after they won the second general election it was as if some of the fight had gone out of him. That might not appear so for someone on the receiving end of his letters in the BBC.
"But by that stage of the three musketeers who were with the Prime Minister, Anji Hunter, Peter Mandelson and Alastair Campbell, Campbell was the only one left.
"This does look like a pre-emptive strike where he gets his resignation in first."
Michael Brown, Former Conservative MP and now political commentator, The Independent
"I'm mildly surprised that he has chosen to do it today but I'm not entirely reaching for the smelling salts. It really is the case that in order to draw a line under the events of the last few months Alastair Campbell probably really does need to make a clean break with Tony Blair.
"He will be greatly missed by Tony Blair. It's like having Tony Blair's brain literally taken out and how he's going to be able to continue without Alastair Campbell is going to be very interesting to watch.
"More than Bernard Ingham [Margaret Thatcher's longstanding press secretary] Alastair Campbell has been taking vital political decisions, offering vital political advice to the prime minister throughout that period."
"That is why it is going to be very interesting to see how Tony Blair manages to move on without Alastair Campbell at his side."
Peter Wilby, editor, News Statesman
"While Labour were still in opposition, Alastair Campbell did a tremendous job in recognising the immense importance of the media agenda. He saw how policy had to be presented to get Labour elected in 1997.
"But I think from maybe 1998 or 1999 he became counter-productive.
"The type of presentation you need to get elected is quite different from that you need in government.
We have seen this with the war in Iraq where you can't distinguish between spin and policy.
"Tony Blair knew that he would find it difficult to convince the public so he wanted to tell them a story of a tyrant who threatened the world.
"The spin became the policy."
Polly Toynbee, political commentator, The Guardian
"Without Alastair Campbell, life gets lonelier and lonelier at the top for the prime minister. After six years, Tony Blair has very few close friends around him.
"They have been winkled out or fallen away. Peter Mandelson may be still there in the shadows but now Alastair has gone too.
"These were people that the prime minister could put his feet up on the desk with and say absolutely what he wanted in absolute confidence.
"I think that Campbell has done a lot of soul searching. When he moved himself to the backroom (giving up his spokesman role) he wanted to take spin out of the story.
"If the public saw the way a mostly hostile press attack the Number 10 spokesmen like a pack of wolves then they would understand that it takes an extremely strong person to withstand that.
"But the press also adored him when he did the lobby briefings. They were grief-stricken when he moved to the backroom and they will miss him."