Gordon Brown invented a "specious and unjustified conspiracy theory" that the Tories did a deal with Rupert Murdoch's media empire because of his anger at being dumped by The Sun, David Cameron said today.
In a blazing rebuke to his Labour predecessor at 10 Downing Street, the Prime Minister told the Leveson Inquiry into press standards that the claim was "absolute nonsense from start to finish".
Mr Brown claimed in his evidence to the inquiry earlier this week that there had been an "express deal" to cut funding to the BBC and media regulator Ofcom in return for more political support from News International titles.
But an angry Mr Cameron dismissed it, saying it resulted from the fact that Mr Brown had been "very angry and disappointed" at the decision of The Sun to switch support from Labour ahead of the 2010 general election.
"He has cooked up a specious and unjustified conspiracy theory to justify his anger."
There had been neither overt deals, covert deals, and no "nods and winks" and no question of "trading policies for that support".
Former Sun editor Rebekah Brooks sent a text message to Cameron telling him "professionally we are all in this together", the inquiry was also told today.
The text was read out by the inquiry's counsel Robert Jay QC as he grilled Mr Cameron about his close friendship with Mrs Brooks - questioning which the previously assured premier appeared more uncomfortable dealing with.
Sent on the eve of Mr Cameron's speech to the Conservative Party conference in 2009, and just days after The Sun switched its support to his party from Labour, it said: "I'm so rooting for you tomorrow not just as a proud friend but because professionally we are in this together. Speech of your life? Yes he Cam!"
Asked to explain the message, Mr Cameron said: "The Sun had made this decision to back the Conservatives, to part company with Labour.
"The Sun wanted to make sure it was helping the Conservative Party put its best foot forward with the policies we were announcing, the speech I was making. That's what that means."
He went on: "We were friends. But professionally, me as leader of the Conservative Party, her in newspapers, we were going to be pushing the same political agenda."
Mrs Brooks yesterday made her first appearance in court on charges of conspiring to pervert the course of justice over the phone hacking scandal.
The text also showed something of the personal relationship the pair enjoyed, with Mrs Brooks saying: "But seriously, I understand the issue with The Times. Let's discuss over country supper soon.".
She also talked about Mr Cameron's failure to attend a conference party thrown by NI - for which he told the inquiry the message was a reply to his apology.
"On the party it was because I had asked a number of NI people to Manchester post endorsement and they were disappointed not to see you," she wrote.
Referring to his wife, she went on: "But as always Sam was wonderful (and I thought it was OEs that were charm personified)."
It is suggested that the abbreviation refers to Old Etonians. Mr Cameron and her racehorse trainer husband Charlie were pupils at the elite public school together.
Mr Jay said the text message had been supplied as the result of a Section 21 request to NI - "requiring people to disclose material".
In her own evidence, Mrs Brooks said she had been able to access only a limited number of her personal communications after resigning over the phone-hacking inquiry.
Mr Jay said it was one of a batch from October 2009 to May 2011 but it was the only one relevant to the line of questioning.
It was partly redacted, apparently removing a personal part of the text at the start.
In the course of an extended grilling over his close personal ties to Mrs Brooks, Mr Cameron repeatedly said that he could not be certain how frequently they met or spoke by telephone.
"I do not think every weekend, I do not think most weekends. But it would depend," he said.
The frequency rose after she began seeing Mr Brooks and moved into his home, becoming a near neighbour of the Camerons in Oxfordshire.
Nor was he able to say even approximately at what point he believed she had become sympathetic to his party's cause, though he accepted it was more than weeks before the formal announcement of the Sun's support.