LONDON — In a stunning retreat, Rupert Murdoch’s News Corp. media empire dropped its bid today to take over full control of British Sky Broadcasting amid a political and legal firestorm over phone hacking at one of its British newspapers.

Murdoch stepped back from making potentially his biggest, most lucrative acquisition, accepting that he could not win British government acceptance of the takeover since the country’s major political parties had united against it.

“It has become clear that it is too difficult to progress in this climate,” News Corp. deputy chairman and president Chase Carey said in a brief statement to the London Stock Exchange.

Shares in BSkyB dived 4 percent lower after the announcement, but quickly rebounded to trade around 1 percent down.

Hours earlier, Prime Minister David Cameron announced he was putting a senior judge in charge of an inquiry into phone hacking and alleged police bribery by one of Murdoch’s British tabloids, News of the World. The British leader also vowed to investigate an allegation that a U.K. reporter may have sought the phone numbers of 9/11 terror victims in a quest for sensational scoops.

“There is a firestorm, if you like, that is engulfing parts of the media, parts of the police, and indeed our political system’s ability to respond,” Cameron said in the House of Commons. He said the focus must now be on the victims — police say they will be contacting over 3,700 people in the probe — and making sure the guilty are prosecuted.