Too many journalists willingly took the poison Mr Campbell offered them

News organisations ought to have the moral courage to insist that their journalists never become press officers' poodles

Most public figures adopt a persona which is only a partial relationship to their private selves. From Alexander the Great onwards, great generals have often done something similar; John Keegan described it in The Mask of Command. For generals and politicians, a mask has a double advantage. It enables them to project themselves to their troops, or their voters. It also ensures that the insults which are hurled at them hit the mask, which bruises much less easily than the man. John Major never had a mask: one reason why his Premiership was so unhappy.

The mask also has a grave disadvantage. It can take over the man. Like a great actor who has poured so much into an all-engrossing role that there is nothing left for himself, the politician may find it impossible to disentangle himself from the part which he was playing. Margaret Thatcher is an obvious example. Once she was thrown out of office, she often sounded like a parody of herself.

Alastair Campbell has a similar problem, for his persona has little relationship to his former personality. Before he donned the mask, Mr Campbell was a likeable fellow and something of an idealist, with strongly held Old Labour views. For the past nine years, he has revelled in projecting himself as a cynical, bullying amoralist. Assuming that he does want to change, it will be interesting to see whether he succeeds.

The same is true of the Blair government, now that the Campbell masquerade is over. The PM's intentions are already plain. He will admit that his government has, perhaps, on occasion, been so keen to tell the country about its achievements that it was over-enthusiastic about the way it explained itself. All that is now in the past, however. In future, the Blair government will let its legions of good deeds speak for themselves. That is how they will spin Mr Campbell's departure.

But whatever they say, they will have two major problems. In the first place, it will be far harder for the Blair government to disentangle itself from the mask than it will be for Mr Campbell. What would be left if the spinning were to stop? The Blair government and its spin machine are not even Siamese twins. They are one creature.

The second problem relates to Mr Campbell himself. His manic energy was the Blair government's motive force. From 6am to midnight, in his relentless efforts to slalom the Blair government from headline to headline, he was spinning, plotting, manipulating; firing off rude e-mails to officials, shouting at ministers, sometimes being fairly brusque with the PM himself. As a result, the machinery of government has become dependent on his input. Without Mr Campbell, there will be a loss of momentum.

This is not to suggest that David Hill, Alastair Campbell's successor, is idle or lacking in ability. He is neither. A completely different character, however, he will not make the mistake of trying to imitate Mr Campbell's modus operandi. Mr Hill will be a much more conventional press officer. He will try hard to keep his own name out of the headlines; he will not try to become the Deputy Prime Minister. But someone will have to; that post should not be left to John Prescott.

So we can dismiss any idea that the government could treat Mr Campbell as a sponge, to be discarded after it has soaked up some poison. Alastair Campbell was much more important than that. He is also much less to blame for the poison than his detractors would claim. He was only able to behave as he did because others let him get away with it.

That is especially true of his relations with the press. Alastair Campbell has often been accused of intimidating journalists, and was undoubtedly guilty as charged. So what? As no self-respecting journalist should never allow himself to be intimidated, it is the victims who should be blamed, not Alastair Campbell. The ascendancy which he achieved over large areas of the press, as well as the BBC, is not to the media's credit.

Mr Campbell could undoubtedly make life awkward for journalists who did not buy his act, most notably by withholding stories from them and giving them to their rivals. But he is by no means the first press officer to behave in this way. News organisations ought to have the moral courage to insist that their journalists never become press officers' poodles.

As for individual journalists who allowed themselves to be bullied, they deserved everything they got. One could only hope that the dishonour of spinelessness was mitigated by the pleasures of masochism.

But Alastair Campbell did not only bully. He also seduced: another shameful period in the history of modern journalism. From 1994 onwards, Alastair Campbell ran a brilliant operation to use right-wing journalists to undermine the Major government and thus ensure Tony Blair's election. Given his views, Alastair Campbell cannot be blamed for trying to induce people who regarded themselves as Tories to join with him in trying to wreck the Tory party. They can be blamed, for their spaniel posture. Mr Campbell's only problem was containing his laughter while his useful idiots strutted their naivety.

When it came to poisoning the wells of government, Mr Campbell is much less innocent. But if there were to be a public inquiry to determine who was responsible for the perversion of good government into shameless spinning, Mr Campbell would not face a lone condemnation. He could only behave as he did because Tony Blair allowed and encouraged him to do so. Admittedly, it often seemed as if the PM was psychologically dependent on his press spokesman. But Mr Blair is a grown-up politician; Alastair Campbell cannot be accused of the corruption of minors.

I have had little to do with Mr Campbell for the past nine years. Curiously enough, he did not think that it would be fruitful to try to spin me. But he did once phone up. I assumed that I was about to be blasted for something that I had written, and prepared to enjoy the process while retaliating. I was wrong. It was much more painful than that. Alastair had just called up for a chat. He commiserated with me on the hopelessness of the Tory party's PR machine. "These people don't seem to realise that opposition is a serious business,'' he said. I found it impossible to disagree.

It was at a profoundly depressing moment. The Prime Minister's press spokesman was so confident in his mastery of events that he had the time to patronise the Tory party - and I was forced to agree with him.

Alastair did not always spin or bully. He could be a genial fellow when he chose, and that is a choice which he will be able to make more often in future. But whatever his personal qualities, he was a wholly bad influence on the British system of government. He has compromised the independence of the civil service, while encouraging those responsible for the release of information to economise with the truth.