Ex-Labour Prime Minister Gordon Brown has denied News Corp chairman Rupert Murdoch's claim that he threatened to "make war" on the media company.
Mr Murdoch told the Leveson Inquiry Mr Brown had phoned him in 2009 after the Sun moved to back the Conservatives.
He quoted Mr Brown as saying: "Well, your company has declared war on my government and we have no alternative but to make war on your company."
But later, Mr Brown responded by saying the allegation was "wholly wrong".
Mr Murdoch had claimed that Mr Brown had not been in a "balanced state of mind" when he made the phone call.
Mr Brown said he did not phone, meet, or write to Mr Murdoch about the Sun's decision to support the Conservatives.
"The only phone call I had with Mr Murdoch in the last year of my time in office was a phone call specifically about Afghanistan and his newspaper's coverage of the war," he said.
"I hope Mr Murdoch will have the good grace to correct his account."
In his written witness statement to the inquiry, Mr Murdoch described attending breakfast and lunches with Mr Brown in which politics and policy were discussed. He added: "I am afraid that my personal relationship with Mr Brown suffered after the Sun no longer supported him politically."
Mr Murdoch said he had frequently met Tony Blair when he was prime minister.
The media mogul said he regarded Mr Blair as a personal friend and enjoyed speaking to him before, during and after his time as prime minister.
In his written statement, he recalled the then-Labour leader speaking "convincingly about the ability of a new Labour Party to energise Britain" at a News Corp conference in 1995.
"Mr Blair did not expressly request our support in 1995, 1997 or any other election, but he was a politician and I had no doubt that he would welcome the support of our newspapers and our readers," he said.
"I want to say that I, in 10 years of his power, never asked Mr Blair for anything.
"Nor indeed did I receive any favours. If you want to check that, I think you should call him."
Meanwhile, Culture Secretary Jeremy Hunt's special adviser Adam Smith has quit after Rupert Murdoch's son James on Tuesday revealed details of contacts between Mr Smith and senior figures at News Corp, while the firm was bidding to take control of BSkyB.
But Mr Hunt has rejected calls for him to resign, telling the Commons he had "strictly followed due process" in overseeing the bid.
In his written statement, Mr Murdoch said he first met David Cameron, who was then Leader of the Opposition, at a family picnic at his daughter's country home.
They did not discuss politics as they were surrounded by children, Mr Murdoch said. Mr Cameron visited him at his offices in Wapping, east London, some time later at the Tory leader's request.
Mr Murdoch said: "Mr Cameron, since his election as prime minister, I have met principally in social settings, where little of substance was discussed."
The News Corp chairman said he could not remember meeting Mr Cameron on a yacht near the Greek island of Santorini in August 2008, but that his wife Wendi could.
'A complete myth'
Counsel to the inquiry Robert Jay QC asked Mr Murdoch if he had discussed policy such as broadcasting regulations with Mr Cameron.
"Mr Jay, you keep inferring that endorsements were motivated by business motives and if that had been the case we would have endorsed the Conservative Party in every election," he said. "But I didn't. I was interested in issues."
"I want to put it to bed once and for all, that that is a complete myth… that I used the influence of the Sun or the supposed political power to get favourable treatment."
He said the perception of his influence over politicians irritated him.
"Because I think it's a myth. And, everything I do every day I think proves it to be such. Have a look at - well it's not a problem - but how I treat Mayor Bloomberg in New York - sends him crazy. But, we support him every time he runs for re-election."
Mr Murdoch also denied ever discussing with Mr Cameron News Corp's bid for the 61% of UK broadcaster BSkyB it did not own.
He said there was no link in his mind between his support for the Conservatives and News Corp's bid.
Mr Murdoch said he had no strong feelings over the Scottish National Party (SNP) - despite The Sun in Scotland backing them in the last general election.
He denied that any deal had been done with the party's leader, Alex Salmond, who he said was "an amusing guy" with whom he had a warm relationship.
The inquiry yesterday considered claims made in an email from a senior News Corp figure suggesting Mr Salmond would call Culture Secretary Jeremy Hunt "whenever we need him to".
Mr Salmond denied any wrong-doing over the BSkyB takeover bid, saying he would be "delighted" to appear before the Leveson Inquiry.
Earlier, Mr Murdoch denied asking or being offered any favours when he met then-Prime Minister Margaret Thatcher at a lunch in 1981, at the same time his company was buying The Times and Sunday Times newspapers.
He admitted he was a "great admirer" of Baroness Thatcher, whom the Sun supported in the 1979 general election.
Counsel Robert Jay QC suggested Mr Murdoch wanted to show Mrs Thatcher he had the will to take on the unions over his bid for the Times and Sunday Times.
But the media mogul replied: "I didn't have the will to crush the unions, I might have had the desire, but that took several years."
Asked about the News of the World, which was forced to close in the wake of the phone-hacking scandal, Mr Murdoch said he was "sorry to say" he "never much interfered" with it.
Mr Murdoch said he tried very hard to set an example of ethical behaviour and made it clear he expected it.
He said he did not believe in using hacking or private detectives because it was a "lazy way of reporters not doing their job".
But he added: "I think it is fair when people have themselves held up as iconic figures or great actors that they be looked at."
In his witness statement to the inquiry, Mr Murdoch also confirmed that News Corporation's Management and Standards Committee was co-operating with the US Department of Justice.
The news comes after reports that investigations into phone-hacking allegations could extend to the US authorities.