The closeness of David Cameron's links to the Murdoch media empire were further exposed today when it was revealed Rebekah Brooks told him they were "definitely in this together".
Her text message to the then opposition leader, in which she said she was "rooting for" him personally and professionally, was among missives demanded from News International (NI) by the Leveson Inquiry.
It provided the backdrop to an uncomfortable period of questioning for Britain’s Prime Minister at the probe he ordered into press standards in the wake of the phone-hacking scandal.
In an all-day interrogation, he said he was haunted by the appointment of ex-News of the World editor Andy Coulson as his spin chief, accused Gordon Brown of inventing anti-Conservative "conspiracy theories" and defended his handling of Jeremy Hunt.
He also said he hoped the review would result in a press regulation system with "real teeth" to punish offenders, setting the acid test of success as whether families like that of murder victim Milly Dowler felt they were now protected.
Mr Cameron's close personal friendship with Mrs Brooks has proved extremely uncomfortable for the premier - the ex-News International chief executive revealing in her evidence that he sometimes signed them off "LOL" to signify "lots of love".
The previously-assured Tory leader failed several times to give a clear answer as to how frequently the pair met when, as leader of the opposition, he was attempting to win over the support of the Sun newspaper, which she edited.
It took a lunch-break consultation of his wife Samantha's diary for him to produce a firmer answer.
The new text message, part of a batch retrieved by NI from Mrs Brooks' BlackBerry records, was sent on the eve of Mr Cameron's 2009 party conference speech and just days after the Sun announced it was switching its support from Labour.
Mrs Brooks wrote: "I am so rooting for you tomorrow not just as a proud friend but because professionally we are definitely in this together."
She went on: "Speech of your life? Yes he Cam", a take on a Barack Obama slogan that was used two days later as the Sun's headline to its report of the speech.
Earlier in the message - part of which was blacked out because it was too personal for the inquiry - she said she understood about an unspecified "issue with The Times" and suggested discussing it "over country supper soon".
The pair are near neighbours in rural Oxfordshire.
Asked about the tone of the message of support, Mr Cameron said: "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."
His message to which she was replying has not been seen. Downing Street said Mr Cameron had been asked to provide Leveson with any text messages relevant to his inquiry but a search of records found none.
Mrs Brooks yesterday made her first appearance in court on charges of conspiring to pervert the course of justice over the phone-hacking scandal.
During the five-hour session, Mr Cameron defended the way he had handled the controversial appointment of Mr Coulson and the decision to give Mr Hunt responsibility for the BSkyB deal.
While admitting his decision to take on Mr Coulson after his resignation as editor of the News of the World had come back to haunt him, the PM insisted he had been given the assurances he needed over phone hacking.
Those pledges had also been accepted by the police, courts, a Parliamentary committee and the Press Complaints Commission, he insisted.
Officials had also backed his decision to assign power of the News Corporation bid for full control of BSkyB to the Culture Secretary in the wake of Business Secretary Vince Cable's secretly-recorded declaration of war on the Murdoch empire, Mr Cameron argued.
"I accept there was controversy but I think the backing of two permanent secretaries and a lawyer is quite a strong state of affairs," he said.
Mr Cameron also launched a robust attack on his predecessor Gordon Brown, accusing him of inventing 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.
He rejected suggestions that while there was no covert deal, there may have been behind the scenes influence of policy.
In terse exchanges, Mr Cameron warned Inquiry counsel Robert Jay QC he was straying into "witchcraft trials" territory, adding: "How do you possibly prove you are innocent on that basis?"
Mr Cameron did concede, however, that the relationship between the rress and politicians had gone wrong over the past 20 years.
That must be fixed through an independent form of regulation with tough powers of redress, Mr Cameron suggested.
But he indicated he was not keen on introducing a statutory system to govern newspapers.
He insisted any new system must protect ordinary members of the public, like the family of murdered schoolgirl Milly Dowler, who have suffered press intrusion or inaccuracy.
"If families like the Dowlers feel this would have changed the way they were treated, we will have done our job properly," he said.