David Cameron and Chancellor George Osborne are among a list of political heavyweights due to appear before the Leveson Inquiry next week.
The Prime Minister has been called to give evidence to the probe into media ethics at the Royal Courts of Justice in London on Thursday.
Ex-PM Gordon Brown and Mr Osborne will be first up on Monday, followed by Labour leader Ed Miliband, his deputy Harriet Harman and former prime minister Sir John Major on Tuesday.
On Wednesday, Deputy Prime Minister and Liberal Democrat leader Nick Clegg will take the stand, as well as Alex Salmond, leader of the Scottish National Party.
Mr Cameron is likely to be questioned about his relationship with the media, News Corporation chief executive and chairman Rupert Murdoch, and his friendship with former News Of The World editor Rebekah Brooks.
The PM is also likely to be grilled over his decision to hand Culture Secretary Jeremy Hunt the responsibility for overseeing News Corp's BSkyB bid.
At the last hearing on May 31 before a one-week break, Mr Hunt survived a six-hour grilling over his handling of the process .
Mr Cameron judged afterwards that the cabinet minister had acted "properly" and decided not to order an investigation into whether he had breached the ministerial code of conduct.
Mr Hunt also insisted there was no reason for him to quit, insisting he handled the bid with "scrupulous fairness" - though he admitted in his evidence that he had considered resigning.
He also suggested he regretted text messages he exchanged with senior figures from News Corp.
The inquiry also heard he sent text messages to Mr Osborne expressing his fears the Government was going to "screw up" the deal when secret recordings of Business Secretary Vince Cable "declaring war" on News Corp emerged.
Mr Cable was later stripped of his responsibilities for the media.