Rebekah Brooks has denied that The Sun hacked the medical records of Gordon Brown's four-year-old son - and refused to disclose the source of the information to the Leveson Inquiry
She also insisted that the paper had permission from the former Prime Minister and his wife before publishing an article about the child's medical condition.
Brooks said that she and Gordon's Brown wife Sarah "were good
In a written response to the Inquiry's questions submitted in October last year Brooks set out a detailed description of safeguards put in place to check stories.
The former tabloid editor and News International chief executive also denied commissioning any computer hacking or feeling any "negative pressure" from proprietor Rupert Murdoch.
Much of the 12-page statement consists of explanations of the processes used to check accuracy and sources, train staff and decide whether to run a particular story.
Despite those efforts, there were "failures from time to time" - significantly so at the News of the World, Mrs Brooks conceded.
"I was horrified when I learned of them and I was and am deeply sorry about the further anguish that was caused to Milly Dowler's parents in particular," she wrote.
Corporate governance was taken "seriously" within the newspaper group though, she added.
Mrs Brooks also told the inquiry:
:: She was not aware of any use of computer hacking: "I have been specifically asked by the Inquiry whether I or the newspapers where I worked ever used or commissioned anyone who used 'computer hacking' in order to source stories or for any other reason. I did not and I was not aware of anyone at either the News of the World or The Sun who did."
:: There was a crackdown on the use of private investigators following highly critical reports by the Information Commissioner's Office and the Commons media and sport select committee.
"I believe their use is now virtually non-existent," she wrote - noting there were exceptions such as using them to track down convicted paedophiles who had broken their bail conditions.
:: The use of cash payments had been "considerably tightened up".
:: It would be "highly unusual and not practical" for an editor to check the accuracy and sources of stories going into their paper other than the biggest or most controversial.
:: There were "numerous examples" of times when she resisted publishing a story because the invasion of privacy outweighed any public interest or because it was more important to alert the police to criminal activities than to secure an exclusive.
"It is quite wrong to believe that the press simply publishes what it can get away with, irrespective of the ethical requirements," she insisted.
:: The industry felt privacy laws had "slowly crept in through the back door", stymieing legitimate journalism but failing to regulate inaccurate internet gossip.
:: In her decade as a national newspaper editor she "never experienced or felt any negative pressure either financial or commercial from the proprietor. In fact the opposite is true. There was always constant advice, experienced guidance and support available." There was no financial motive to print exclusive stories. "Professional pride was the biggest incentive."
Brooks says talks with Osborne were 'brief'
Earlier, she insisted she had only "brief and inconsequential" discussions with Chancellor George Osborne over parent company News Corp's bid to take over BSkyB.
And she denied ever having "inappropriate" conversations about Rupert Murdoch's efforts to buy the remaining 61% of the satellite broadcaster with anyone who might be in a position to influence the Government's decision.
The issue of contacts between Mrs Brooks and the Chancellor was raised by the release of emails from News Corp lobbyist Frederic Michel by the Leveson Inquiry last month, which included one in which she reported Osborne's reaction to an Ofcom announcement on the BSkyB bid: "Same from GO - total bafflement at response".
In a written statement to the inquiry today, Mrs Brooks said she could not remember sending the email, but assumed that the initials GO referred to the Chancellor, who her records show she met "socially" the previous evening.
But she played down the significance of her comment, telling Leveson: "The email clearly shows that whatever was discussed was brief and inconsequential. The issue was topical and of course everyone would have known that, as the CEO of News International, I would have been likely to support the bid."
Mrs Brooks said in her statement that she had no official role in the BSkyB bid, which did not involve News International, but found herself "drawn into the debate" and would certainly have discussed it at the Conservative conference in October 2010.
"When the matter arose in conversation, I am sure that I would have expressed my views forcefully, particularly given the vocal opposition," wrote Mrs Brooks. "I have no doubt whatsoever that opponents of the bid were doing likewise.
"At no point did I ever have an inappropriate conversation with anyone who had any influence over what the Government might do."
Mrs Brooks insisted there was "nothing wrong" in her, as editor of The Sun and News of the World, forming friendships with senior politicians and meeting them socially as well as professionally. Regular contact between the press and politicians - as well as public officials and police chiefs - was "of vast importance to our democracy" and any suggestion they should not meet was "entirely wrong", she said.
In her written statement to the inquiry, she said she had "numerous" meetings" with David Cameron and Tony Blair and formed a "close friendship" with both Cherie Blair and Gordon Brown's wife Sarah.
But she suggested that reports about a "pyjama party" hosted by Mrs Brown for her and Rupert Murdoch's daughter and wife at the PM's country residence Chequers were overblown.
"The year I turned 40, Sarah was concerned that I had not planned any birthday celebrations," wrote Mrs Brooks. "That same year, both Elisabeth Murdoch and Wendi Murdoch also celebrated their 40th birthdays, and so Sarah invited all three of us with some mutual friends to have dinner at Chequers and, due to logistics, to stay over that night and leave after breakfast.
"That is the extent of the so-called 'slumber/pyjama party'. Gordon Brown was not present at the dinner, but he may have been there the next morning before we all left."
Mrs Brooks said she had met every leading politician at some point or other while a newspaper editor, describing Mr Blair and his advisers and ministers as "a constant presence in my life for some years".
She became "close friends" with Mrs Blair, as well as Alastair Campbell and his partner Fiona Miller, though she described her contacts with Mr Brown as "a working relationship".
Mrs Brooks recalled meeting Mr Cameron "at numerous political and social occasions (including working breakfasts, lunches, receptions, News Corporation summer parties, party conferences and dinners)" and speaking regularly to him on the phone while he was leader of the opposition.
But she had not been to Downing Street and had few formal meetings with him since he became Prime Minister, seeing him "mainly at social events, celebrations or other occasions".
Following her 2009 marriage to Charlie Brooks, an old family friend of the Camerons, she became friends with the PM. He was a personal guest at social dinners at the Brooks's home, including on December 19 2009 and December 23 2010, and she visited him at Chequers and met him at the homes of other friends and family.
In her statement, Mrs Brooks emphatically denied that these friendships were in any way untoward.
"It is important to understand... that close and effective working relationships must not lead to compromise on either side," she wrote.
"I have never abused my friendships to gain access to information that otherwise I could not have obtained as a professional journalist, nor have I ever compromised my independence through loyalty to a friend who is also a politician.
"But whether a relationship develops into friendship or not, a relationship of trust and confidence between the press and politicians does have great value. Where I have known a politician well, this has led on many occasions to a free and frank exchange of views as we have sought to change policy or better understand why the Government is taking a particular stance.
"If our relationship were always confrontational and antagonistic, we simply would not engage with politicians to that degree. Equally, an amicable relationship often helps, particularly in decisions in publishing stories of a personal nature."
Mrs Brooks said that she believed her lobbying and campaigning as an editor helped influence Government policies on issues like domestic violence and the right for parents to be informed of paedophiles living in their area.
But she dismissed as a "myth" the idea that she was able to dictate decisions on ministerial appointments and said she did not believe that newspapers were able to change the result of elections. Their decisions on who to endorse were more important as "an early indication of the outcome", she said.
While Mr Brown regarded The Sun's 2009 endorsement of Mr Cameron for Prime Minister as a "betrayal", Mrs Brooks said it was "fairly inevitable" given the paper's opposition to his policy platform.
Mrs Brooks pointed out that her husband Charlie, a contemporary of the Prime Minister at Eton, had longstanding family links with the Camerons separate from her own connections.
She stressed that details of the meetings came from her secretary's diary and were "very incomplete", as she had no access to records at her former company.
Asked whether she discussed the phone-hacking scandal with Mr Cameron between details emerging of pay-offs to victims in July 2009 and her resignation last year, Mrs Brooks said: "I think on occasion and not very often. So maybe once or twice because the phone-hacking story was sort of a constant, or it kept coming up.
"We would bring it up but in the most general terms ... Maybe in 2010 we had a more specific conversation about it."
Mrs Brooks went on: "It was to do with the amount of civil cases coming in around 2010 and we had a conversation about that...
"It was a general discussion... I think it had been in the news that day and I think I explained the story behind the news."
Asked whether Mr Cameron's interest was related to the position of his then-spin doctor Andy Coulson, Mrs Brooks said: "No."
Mrs Brooks was also questioned about Rupert Murdoch's attempt to take full control of BSkyB, and said she knew of it a "couple of months" before it was made public in June 2010.
Asked if she discussed the issue with Mr Cameron at the dinner at her home in December 2010, she said it was mentioned because it was in the news after Business Secretary Vince Cable was reported to be promising to "declare war" on Mr Murdoch.
The incident led to Mr Cable handing over responsibility for deciding whether to allow the bid to Culture Secretary Jeremy Hunt. It was later dropped.
"I may have mentioned it to Mr Cameron but it is not to be dwelled on because it wasn't a particularly long conversation," she said.
She had a "three-minute conversation" on the topic with George Osborne at dinner in December 2010.
"I put my views that were contrary to the ones that he had heard from everyone else," she added.
The following day Mrs Brooks emailed News Corporation public affairs executive Fred Michel saying that Mr Osborne had expressed "total bafflement" at Ofcom's latest response to the bid.
"It was an entirely appropriate conversation," she insisted. "They were all saying the same thing - 'it is not my decision'."
Mrs Brooks said she did not remember discussing it with Mr Cameron at a mulled wine and mince pie party at her sister-in-law's house on Boxing Day 2010, and she was not sure if they even spoke that night.