The media and not politicians are responsible for 90% of what is commonly called "spin", former Downing Street press chief Alastair Campbell has said.
Campbell is facing MPs
Labour should have left some techniques in opposition, he told MPs, but the media had to realise it had to change.
He said the Hutton inquiry had made him favour more freedom of information.
It had shown people could make up their own minds whatever newspapers said if government's inner workings were published, Mr Campbell argued.
He also said Daily Mirror editor Piers Morgan's position would be "untenable" if the newspaper's pictures of alleged abuse of Iraqis by UK troops proved to be fakes or staged for political or commercial reasons.
Tony Blair's former media director, who left No 10 last year, was questioned as part of the Commons public administration select committee's inquiry into government communications.
The recent Phillis review of the government's media network suggested the way special advisers had become more powerful under Labour, using "aggressive" methods, had led to a more adversarial approach from the media.
Mr Campbell said he accepted some of the Phillis analysis but argued the report had understated the media's contribution to souring the relationship.
He went on to argue that "ninety per cent of what is commonly described and derided as spin is actually put there by the media", who had their own agenda.
Calling relations between the government and the media "very unhealthy", he said: "The politicians are not as bad as the media who cover them."
The former Mirror journalist argued the emergence of 24-hour television news networks had forced newspapers to adapt and they felt they needed to become "campaigning machines".
The government had introduced changes, such as Mr Blair's monthly news conferences, to make the system more open, he said. And there were many good journalists in Britain.
"But until the good stand up to the bad and actually say this driving negativity is doing nobody any good, including the media, nothing is going to change," he said.
Mr Campbell was a key witness in the Hutton inquiry, which cleared him of "sexing up" the government dossier on Iraq's alleged weapons of mass destruction.
The inquiry published reams of Whitehall documents, a process the ex-media chief said had helped convert him to promoting more freedom of information.
Newspapers had "spun" the inquiry evidence according to their view of the Iraq war but anybody fairly looking at the documents would conclude the government had come out "pretty well", he claimed.
"So I think maybe the lesson from that is just don't worry so much about what the papers are going to be saying about what comes out in the public domain," he said.
"Just be more trusting of the public because I think they are canny enough to see where they are being spun a line, wherever it's coming from, whether it's a politician or a newspaper."
Mr Campbell rejected suggestions he had "lost control" in the furore which led to the Hutton inquiry, saying he had needed to rebut the BBC's weapons story.
The prime minister has been criticised by some ex-ministers for relying too much on a close circle of advisers in Downing Street.
But Mr Campbell said government was political and it was "cloud cuckoo land" to imagine that any prime minister or secretary of state did not have a small number of like-minded people around him.
Daily Mail editor Paul Dacre has already told the MPs' inquiry that Mr Campbell's media operation provoked media cynicism.
Mr Campbell called the newspaper "vile", saying: "It systematically undermines and runs down the country and people in public life."