Later, in a transparent attack on Cameron's Tories, he attacked the "old toffs and right wingers who still want last century's status quo."
Media analyst Steven Hewlett said Murdoch had plenty of incentive to embarrass Cameron, or perhaps even Britain's entire ruling class.
"There's a feisty, slightly annoyed side to Rupert," Hewlett said. With the inquiry likely to focus on whether Murdoch used his power and access to lobby for regulatory favors, Murdoch could turn the question on its head by detailing how politicians tried to lobby him for favorable coverage.
"Rupert will say: 'It takes two to tango,'" Hewlett predicted.
Politicians in the United States and Australia — where Murdoch also wields considerable influence — may find the testimony compelling.
Media pundit Paul Connew said that next week would provide "fascinating theater" and attract "massive international media coverage."
Observers may also want to take note of the action taking place behind the scenes.
Police and prosecutors are considering the first batch of charges against those involved in the scandal, which may come in the second half of May, according to two people briefed on their progress.
And lawmakers on Parliament's media committee are putting the final touches on their report on the phone hacking scandal. The document is expected either to blast James Murdoch for failing to get a grip on the scandal or excoriate his lieutenants for keeping the 39-year-old executive in the dark.
Lawmaker Paul Farrelly has said that the report — which has been delayed for months — is tentatively due out May 1.
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