Father-and-son act Rupert and James Murdoch top the bill tomorrow in what promises to be a day of gripping political drama in the normally staid surroundings of the British parliament's committee rooms.

It will be the first time the Murdochs have been questioned in public since a newspaper phone hacking scandal reignited two weeks ago, sparking a firestorm that has raged through their News Corp media empire, brought down Britain's top policeman and tarnished prime minister David Cameron.

The hearing, likely to attract an audience of millions via the live news channels of the BBC and Sky - part-owned by News Corp - is a further chance for politicians to show they have broken Murdoch's spell after decades spent trying to win favour with the media mogul.

The British parliament has a renewed sense of purpose, two years after it was plunged into scandal by reports in another newspaper of widespread fiddling of expenses by MPs.

However, it must not overplay its hand when the camera-shy Murdochs step before it in what will be a cramped room in the modern Portcullis House annexe to parliament.

"I don't want us to be a lynch mob," said John Whittingdale, the committee chairman, a member of the Conservative party. "On the other hand, I don't want us to let them off without properly addressing the questions which we have," he told BBC TV.

The phone hacking scandal centred on News Corp's News of the World tabloid has rumbled on for several years. The floodgates opened when a lawyer for the family of murdered schoolgirl Milly Dowler alleged the paper hacked her phone when she went missing and deleted some of her messages, giving her family false hope she was alive.

Responding to the crisis, the Culture, Media and Sport Committee last week called in the Murdochs and Rebekah Brooks, chief executive of their News International UK business.

Paul Stephenson, head of London's police, was also asked to appear before the home affairs committee tomorrow at lunchtime, the warm-up act for the Murdoch show.

Since then, Stephenson and Brooks have both resigned their posts. Ms Brooks, a former News of the World editor, spent Sunday in police custody after she was arrested on suspicion of corruption and intercepting communications.

Witnesses before the parliamentary committee sit with their back to reporters and a smattering of political aficionados who normally attend such sessions.

Members of parliament, 10 or 11 in number, sit opposite them behind a horse-shoe shaped desk and question them directly.

Reporters seeking to attend the Murdoch session in the Wilson room are told to have "sharp elbows" at the ready to secure one of only 50 seats for press and public. An overflow room has been set up for those who can't muscle their way in.

The atmosphere will be tense but the Murdochs are unlikely to be skewered in the way then BP chief executive Tony Hayward was when he went before a US congressional committee following the Gulf of Mexico oil spill last year.

"It's a frightening experience. You can really feel like you are in a cauldron and they are trying to trip you up," said one person who has appeared before the British Treasury Select Committee during heated hearings into bankers' bonuses.

The Media committee may feel it has a score to settle with News International in a hearing that will be a prelude to a wider judge-led public inquiry into media ethics.

In a report last year, the committee concluded that it was "inconceivable" that managers at the company did not know that News of the World reporters were getting stories by listening in to voicemails. The reports are non-binding but can influence government policy and helped to keep the story alive.

At a series of hearings in 2009, former News of the World editor Andy Coulson and former News International head Les Hinton maintained that the only phone hacking at the tabloid had been carried out by royal reporter Clive Goodman, who was jailed in 2007.

As allegations have emerged that the practice was rampant and up to 4,000 people's voicemail was intercepted, James Murdoch has been forced to admit he approved out-of-court settlements to victims without a full picture of what had been going on.

"The first reason why we were extremely keen to hear from James Murdoch, Rupert Murdoch, Rebekah Brooks, was the statement by James Murdoch that he now knows that during our previous inquiry parliament was misled. That is something we obviously take very seriously," committee chairman Mr Whittingdale said.

"Therefore we will want to know from him in what way exactly we were misled, who it was and how long that it's been known for, and why it's only now that it's becoming public."