Rupert Murdoch, his son James and Rebekah Brooks, the former News of the World editor who used to run their British newspaper empire News International, face grilling by a committee of MPs later on Tuesday.
They will appear at 1430 BST (1530 CET) in front of ten Members of Parliament, several of whom have publicly criticized them in the past.
The session is the first time either man has appeared in front of the Culture, Media and Sport Committee, despite several previous requests.
Both initially said they could not attend on that date.
"It's an occasion of great drama," Alan Rusbridger, editor of The Guardian, the newspaper which has spearheaded the campaign against phone hacking at the News of the World, told CNBC Tuesday.
"There is not much to gain for the Murdochs or Brooks but there is an awful lot to lose. I think it would have been a PR disaster if they had refused to appear."
"The weakness of a Commons hearing is that they are not like US congressional hearings, there is no counsel so it is not going to be very forensic," he added.
The Murdochs have taken on PR advice from Edelman, and Brooks has hired David Wilson of Bell Pottinger, the London-based PR firm founded by Baroness Thatcher's PR adviser.
Labour MP Tom Watson, one of the members of the committee, has been particularly outspoken.
Prime Minister David Cameron, his deputy Nick Clegg, leader of the Liberal Democrats, and Leader of the Opposition Ed Miliband have all rounded on the Murdochs too.
Cameron and Miliband attended the News International summer party just a month ago, with many other high-profile politicians and journalists.
There was speculation Tuesday that James Murdoch's position as a director of GlaxoSmithKline might be compromised. A spokesman for GSK said that he was still a director at the company.
"With regard to the activities that are alleged to have taken place at News International, we believe that the full facts must be established and the ongoing investigations be allowed to take place and come to a considered conclusion," he added.
After Brooks resigned on Friday, reports suggested that he might be next in shareholders' firing line.
On Monday night, a computer, paperwork and a phone found in a bin near the riverside London home she shares with her husband were examined by police.
"It's an intriguing story," said Rusbridger.
"The police will be asking whether this was an attempt to destroy evidence but the Brooks have absolutely refuted that."
Two of Britain's most high-profile policemen, both of whom have resigned in the wake of the scandal and accusations that the alleged phone hacking was not investigated sufficiently, will appear in front of the Home Affairs Committee. They will also face questions about how Neil Wallis, an ex-News of the World journalist arrested over phone hacking, was hired by the Metropolitan Police as a PR advisor.
News Corporation , the foundation of the Murdochs' fortune, has closed the News of the World, the newspaper whose employees allegedly hacked into a dead schoolgirl's phone, and abandoned its bid for the 61 percent of broadcaster BSkyB it does not already own.
Standard & Poor's has put the company's debt on "ratings watch negative".
"The company had an appearance of completely drifting earlier this year, then in the last two weeks it has looked like a company that was completely out of control," said Rusbridger.
"The judicial enquiry will want to ask how widespread this practice of hacking was. In a small place like Fleet Street where people change from paper to paper and where there's so much competition to get stories people will find that this was not just happening at one paper."
The website of The Sun, the British daily tabloid and former sister newspaper to the News of the World, was hacked by LulzSec Monday night.
Its front page was replaced by a story claiming that Rupert Murdoch had died.
A former News of the World journalist who spoke out about alleged phone hacking was found dead in his home on Monday. The death of Sean Hoare, the showbusiness reporter who was the first journalist to go on the record saying that former editor and David Cameron's ex-head of communications Andy Coulson was aware of phone hacking by his staff, is not being treated as suspicious by police.