Britain's press has failed the country by mixing fact and opinion, Gordon Brown has told the Leveson inquiry.
The former prime minister claimed he had been unfairly "demonised" by journalists at the Sun newspaper over stories suggesting he did not care about troops in Afghanistan.
He said the growth of the internet threatened journalistic standards, hit out at "the excessive dominance of what is called the lobby system" and warned that journalists were invading individuals' privacy excessively in his opening comments to the inquiry.
Mr Brown's biggest concern was over "the conflation of fact and opinion" in newspaper articles, however.
He suggested there had previously been a time when newspapers confined their views to editorials, before concluding: "That's where the press has failed this country."
The ex-New Labour leader said he had had a lot of time to consider the issues involved thanks to "a period of enforced reflection courtesy of the British people".
He rephrased Lord Justice Leveson's question about the fundamental basis of the inquiry, who guards the guardians, by asking: "Who will defend the defenceless?"
And he suggested that state funding along the model of the BBC's licence fee could be used to pay for "quality journalism".
Mr Brown also firmly rebutted News International's defence of its decision to publish a 2006 story revealing that the then chancellor's three-month-old son had cystic fibrosis.
But NHS Fife released a statement confirming News International's claim it had not hacked its way to the story.
"Any breach of confidentiality in the NHS is unacceptable," it said.
"We now accept that it is highly likely that, sometime in 2006, a member of staff in NHS Fife spoke, without authorisation, about the medical condition of Mr Brown's son, Fraser."
Inquiry counsel Robert Jay pointed out Mr Brown's wife Sarah had held a party after the publication of the story which Rebekah Brooks attended because she was "one of the most forgiving people I know".
The ex-prime minister then added: "I couldn't allow what had happened to me to become a huge issue when I had a job to do."
Mr Brown claimed he had been the victim of "underhand and perhaps unlawful" practices by journalists at the Sunday Times newspaper.
"There was no public interest justification for the intrusion and the impersonation and the breaking-into of records," he said.
Mr Brown and News Corp's senior figures, including Rupert Murdoch and Rebekah Brooks, have been engaged in a war of words over their newspapers' decision to abandon New Labour.
Mr Murdoch had claimed that Mr Brown 'declared war' on him after it became clear the Sun was abandoning its support for New Labour.
"This conversation never took place," Mr Brown insisted. "This was a matter that was done. There was no point for any further communication at all."
He claimed that it was his "duty" to meet with newspaper owners and editors, but insisted he had no phone numbers of newspaper proprietors on his mobile phone.
Mr Brown also refused to accept that he had been behind Labour backbenchers' manoeuvring to force Mr Blair's resignation in 2006.
When asked whether his political advisers had been involved in attempts to force the issue Mr Brown replied: "I would hope not. I've got no evidence on that."
He dismissed his former first secretary of state Peter Mandelson's claim that he viewed Damian McBride as his "attack dog", saying: "This is what I mean about tittle-tattle. I don't know the truth of all these things."
Mr McBride was forced to resign after it emerged he was exploring setting up a website which put forward salacious fictional rumours about right-wing politicians.
"Our political advisers worked through the head of communications who was a civil servant," Mr Brown insisted.
In other comments Mr Brown complained that the internet was opening up new opportunities for poor quality journalism.
"I think there is an issue not just about rooting out the bad... I think we've got to have some means by which we incentivise the good as well," he said.
"There is an issue in the internet age about the decline of standards."
Before Mr Brown gave evidence Lord Justice Leveson acknowledged there was "intense public interest" in his inquiry but warned that the questioning would focus on its remit - especially on the relationship between politics and the press.
"I am very keen to avoid inter-party politics and the politics of personality," he said in a statement at the beginning of the week. "I am simply not interested in either."
He repeated an earlier warning about the way in which his inquiry is reported, adding: "It may be more interesting for some to report this inquiry by reference to the politics of personality... that is not my focus and as ever I'll be paying attention to the way in which what transpires is in fact reported."
Mr Brown could not help making partisan points, however. He said it was a matter of "regret" that he had not been able to tackle media regulation issues but pointed out that on every area, including the BBC licence fee and Ofcom's future, the Conservative party supported every one of the recommendations made by the Murdoch group.
His admission of "regret" reflected a broader willingness to accept the failings of his premiership.
At one stage he commented: "I don't think anybody could accuse me of any great deal of success in getting my message across."