And when the daylong political street fighting with the opposition Labour Party was done, he appeared to have at least steadied support within his own party and, perhaps as important, within the ranks of the Liberal Democrats, his nervous coalition partners.

The confrontation in the House of Commons — a day after appearances before a parliamentary committee by Rupert and James Murdoch, whose News of the World newspaper, now defunct, has been at the heart of the scandal — capped a difficult period in which the politically agile prime minister appeared to lose his normally assured demeanor, allowing Labour to get ahead of him in putting an end to the Murdochs’ bid for Britain’s top satellite television company.

Mr. Cameron flew back from a shortened trade trip to Africa on Tuesday and worked late into the night preparing for the showdown over revelations about the tabloid that have exposed cozy and sometimes corrupt relations among the press, politicians and the police, and that have crystallized into the most serious crisis of credibility and confidence of his 15 months in office.

As the eight-hour Commons showdown ended, the prime minister appeared to have quieted the worst anxieties in his Conservative Party, whose most powerful backbench group gave him a desk-banging thumbs up. Several Liberal Democrats, meanwhile, emerged from the session to say that the emphasis should be on reforms to rid Britain of the excesses of its tabloids, and not on efforts to topple Mr. Cameron, unless there were new disclosures implicating him in efforts to stifle the police investigation of the issue or to mislead Parliament.

Only a week ago, the Liberal Democrats seemed to be edging closer to an alternative compact with the Labour Party that could have threatened the government’s survival and its program of harsh spending cuts.

Still, with police inquiries into the affair accelerating, posing the potential for further revelations and arrests, Mr. Cameron may, at best, have only stalled the Labour onslaught that has sought to link him to the scandal through his close ties to Mr. Murdoch and two former editors of The News of the World, one of whom was Mr. Cameron’s communications chief for nine months.

After more than two weeks in which Ed Miliband, the Labour leader, outflanked Mr. Cameron at virtually every turn, the prime minister appeared to hit his stride, coupling incensed denials of personal wrongdoing in the affair with a new, hard-edged attitude toward his former media chief, Andy Coulson, one of 10 people linked to the Murdoch newspapers who has been arrested in the scandal.

Showing an edge of bitterness toward a man he was describing only days ago as a friend, Mr. Cameron said that “with 20-20 hindsight and all that has followed, I would not have offered the job, and I expect that he wouldn’t have taken it.”

“You live and you learn,” he added, “and, believe you me, I have learned.”

Mr. Cameron also took on Mr. Miliband, saying that most of the abuses now under investigation within the Murdoch newspapers took place when Labour was in power and that the Labour governments of Tony Blair and Gordon Brown had taken no action on evidence that serious wrongdoing had occurred. He also said that Labour’s ties with Mr. Murdoch and his executives, and the party’s pursuit of Mr. Murdoch’s political favor, were more extensive than his own.

“I can assure the House that I’ve never held a slumber party or seen her in her pajamas,” Mr. Cameron said, referring to Rebekah Brooks, a onetime editor of The News of the World, who resigned as chief executive of News International, the paper’s parent company, late last week. The gibe referred to a gathering Mr. Brown’s wife held in 2008 at the prime minister’s country retreat, which British newspaper accounts have said was attended by Ms. Brooks; Mr. Murdoch’s wife, Wendi; and his daughter Elisabeth. A Daily Mail account said guests were told to bring their pajamas “for the sort of sleepover usually favoured by teenage girls.”

Mr. Cameron’s defense on Wednesday — and his continuing vulnerability — rested on two potentially explosive issues. First was why he hired Mr. Coulson only months after Mr. Coulson’s 2007 resignation as The News of the World’s editor, then took him to Downing Street, in the face of a flurry of private warnings, after the Conservatives won the May 2010 general election.

Article source: http://www.nytimes.com/2011/07/21/world/europe/21hacking.html?partner=rss&emc=rss