This is shaping up to be a big week at the Leveson Inquiry into UK media ethics: Several high-level politicians are set to take the stand, offering evidence on the relationship between government and big media. Off to a roaring start today with a game of “he said-he said”, former UK Prime Minister Gordon Brown told the hearing room that there was no evidence of a phone conversation between he and Rupert Murdoch in September of 2009. During the disputed call, Brown is alleged to have threatened the mogul. He also took shots at Murdoch’s News International and its former executive chairman, James Murdoch, who Brown said drove an “aggressive public agenda.” He further contradicted testimony given by former Murdoch lieutenant Rebekah Brooks, and said he had never been influenced by Rupert Murdoch. If he had suported Murdoch’s policies, Brown quipped, the UK wouldn’t be part of the European Union, England would be the 51st state of the U.S. — with Scotland the 52nd — and Murdoch “probably would have had us at war with France and Germany.”

Repeatedly denying the September 2009 call took place, Brown said earlier statements made by Rupert Murdoch to the inquiry were “shocking.” Testifying in April, Murdoch said Brown had called him after it emerged that The Sun newspaper would support Brown’s opposition, the conservative party, in the next election. Murdoch said that Brown told him, “Well, your company has declared war on my government and we have no alternative but to make war on your company.”

Murdoch at the time characterized Brown as not being in “a very balanced state of mind.” Brown said he was “surprised” by the story of the call, “There’s no evidence other than Murdoch’s, but it didn’t happen. I had no reason to call him and would not have called him.” Later questioned by a lawyer repping News International, Brown said “I think News International is doing itself a great deal of harm to suggest that a call happened that never happened… News International have produced not one shred of evidence, not one date for the call, not one time for the call… and I find it very strange that we’re being asked to debate a call that never took place.” Following Brown’s evidence, a News Corp spokesperson said “Rupert Murdoch stands behind his testimony.”

Brown did allow that he and Murdoch share a similar background and that the pair had at one time a warm relationship. He also stressed his respect for Murdoch’s business acumen. But, he added that he drew “a line in the sand on any question” related to media. “You can serve up dinner, but you can’t serve up BSkyB as part of the dinner,” Brown said adding, there was no point during his tenure where he would “ever allow a commercial interest to override the public interest.”

It was clear that he “never had the support of The Sun” during his 3 years in office, Brown said. But “what really changed” was “when News International decided that their commercial interests came first,” Brown noted, recalling a speech James Murdoch had given at the Edinburgh International Television Festival in 2009. The Murdoch scion at the time had attacked the BBC and media regulator Ofcom in an address Brown called “breathtaking in its arrogance and ambition.” Brown also noted that his government could not go along with the young Murdoch’s suggestions, but that “while we resisted it, on each of these issues the conservative party supported each and every one of the issues Mr Murdoch raised.”

On Thursday, current conservative Prime Minister David Cameron will spend the day testifying about his links to News Corp as well as ties to former News International chief Rebekah Brooks and former News Of The World editor Andy Coulson, who later became Cameron’s communications director. Chancellor of the Exchequer – and Cameron crony – George Osborne, is testifying this afternoon. John Major, another former UK Prime Minister, gives evidence on Tuesday and current Deputy Prime Minister Nick Clegg is up on Wednesday.