Last November, Lord Justice Leveson recommended "a genuinely independent and effective system of self-regulation" of the press, backed by a new statutory law.
Cameron has subsequently proposed a system involving a new press regulatory body overseen by a royal charter.
Following the breakdown of cross-party talks on the matter, Cameron announced on Thursday (March 14) that MPs would vote on press regulation on Monday night (March 18).
Hacked Off supporter Rowling today (March 17) said: "Some victims of press abuse felt that Lord Leveson did not go far enough; I disagree. As an oft-banned writer, a devoted reader of Private Eye for a quarter of a century and as somebody who venerated the late great Paul Foot, I could not support anything that hampers the press's ability to hold power to account. Lord Leveson's recommendations seemed reasonable and proportionate to me, their aim simply to curtail abuses of the press's own power.
"It goes without saying that what my family has been through - and I spent two hours re-living those experiences on the stand at the Inquiry - is less than nothing compared to what was meted out to the McCanns, the Watsons and the Dowlers: ordinary families who became newsworthy through terrible personal tragedies, or to Chris Jeffries, who was literally in the wrong place at the wrong time and found his life forever changed.
"I believed David Cameron when he said that he would implement Leveson's recommendations 'unless they were bonkers'. I did not see how he could back away, with honour, from words so bold and unequivocal. Well, he has backed away, and I am one among many who feel they have been hung out to dry. Monday's vote will make history one way or another; I am merely one among many turning their eyes towards Ed Miliband and Nick Clegg and hoping that they have the courage to do what Cameron promised, but which he failed to deliver."
Hugh Grant has also spoken out to criticise David Cameron's plans for press regulation.
Immediately after the Inquiry last year, Harry Potter author Rowling said that she felt "duped and angry" and "alarmed and dismayed" by Cameron's response to Leveson.