Rupert Murdoch, unfazed by a foam pie attack in the British parliament, made a "humble" apology on Tuesday for crimes that have rocked his media empire and the government but refused to resign, saying the fault lay with staff who betrayed him. Revelations of phone-hacking and payments to police by the News of the World have raised questions on his family's grip on News Corporation, on the probity of the police and on the judgment of Prime Minister David Cameron, who returned early from Africa for an emergency parliament debate on Wednesday. Calling it "the most humble day of my life", Murdoch defended his record and that of his son, and said he could not know everything that his 53,000 employees did. James, 38, sat beside him before parliament's media committee, interjecting on occasion as his 80-year-old father hesitated to give answers on what he knew, and when, of criminality at the Sunday tabloid. But as three hours of earnest, at times testy, proceedings drew to a close with lawmakers pressing the Murdochs to explain payments to some of those involved in the decade-old affair, the hearing briefly turned to violence and farce when a man rose from the public seating of the packed committee room. As he tried to hit the elder Murdoch with a paper plate of white foam, the Australian-born mogul's 42-year-old wife Wendi Deng leapt in to slap the protester in a melee before he was seized by police. He was identified as a left-wing comedian.