But negotiations between Cameron's Conservatives and others over how to implement those recommendations have stalled amid an increasingly acrimonious debate. Politicians are divided about whether a new press watchdog should be set up through legislation — as recommended by Leveson — or through a Royal Charter, an executive act that does not require a vote in Parliament.
Proponents say passing a law will put the watchdog on a firmer footing and give it more power to discipline rogue newspapers. Opponents believe that passing a media law would endanger the country's free press.
In fact, the proposals aren't all that different. A new law would set up an independent press watchdog, not control the media directly. And the regulator would only have the power to impose fines or demand published apologies from newspapers — not to stop articles being published.
But the language of the debate has been fierce, with opponents fearing the demise of Britain's free press and advocates seeing a bullying media riding roughshod over people's rights.
"The idea of a law, a great, big, all-singing, all-dancing media law ... would have been bad for press freedom, bad for individual freedom," Cameron said.
Rowling accused the prime minister of letting down hacking victims by ignoring Leveson's proposals.
"I believed David Cameron when he said that he would implement Leveson's recommendations 'unless they were bonkers,'" she said. "I did not see how he could back away, with honor, from words so bold and unequivocal.
"Well, he has backed away, and I am one among many who feel they have been hu