The latest knife in the back was the revelation that Campbell still speaks to his old boss twice a week to give advice. As if the Prime Minister isn't in enough trouble, the bad news is that Campbell, having agreed not to produce his diary until the PM has left his job, needs to keep a high media profile.
Campbell openly boasts about being offered more than a million quid for the tome, and expects big Brownie points for turning it down. However, the worst-kept secret in Westminster is his lucrative, exclusive deal with the Murdoch press.
It is his latest offering in the Times that is so damaging to the Prime Minister. The last thing Blair needs as he approaches the Hutton report is the man who is as guilty as anyone in getting him into the mess telling everyone they are as close as ever.
Campbell knew that his claim of regular contact with Blair would be picked up on by astute Times political editor Philip Webster. It wouldn't even surprise me if the two discussed the best line to take. But while it may suit Campbell to tell the world that he is still advising the PM, it doesn't help his old boss. Nor will his replacement, David Hill, be happy. In fact, I'm told he's 'spitting blood'.
Ironically, Campbell is in exactly the same position as former Blairite minister Peter Mandelson, who likes nothing better than to brief hacks on how much he still influences the Prime Minister. I understand why they are so anxious to let it be known that they still have Blair's ear.
They are both people who have achieved little on their own, but much in support of others. You would have thought, though, that Blair would not be so reliant on them now, especially as they both became so damaging for him. Most politicians see their advisers come and go and are all the stronger for it. Blair does the opposite, and seems to get weaker every time he loses one of his bag carriers.
Campbell's deal with Murdoch at least has the advantage of ensuring favourable coverage. I doubt if Campbell could have done a better job of the Times interview if he had written it himself. The interviewer falls hook, line and sinker for the Campbell line that he left voluntarily, and even buys the absurd story that Campbell has a special phone that is only used to take calls from Downing Street.
One thing is clear, though, Campbell hates being out of the limelight and finds life outside Westminster tough. I have some advice for him.
I understand how difficult it is to suddenly find yourself not working 24 hours a day, but there is no going back. If you really admire the Prime Minister as much as you say, turn your mobile phone off and shut up.