Lord Justice Leveson today published his report after an eight-month inquiry into press ethics and standards following the phone hacking scandal at the News of the World.
[Left: Lord Justice Leveson / Right: Bob and Sally Dowler]
The prime minister told Parliament this afternoon that he accepted the principle recommendations of the judge's 2,000-page report, including that an independent body should be established by the industry to tackle the "outrageous" abuses by newspapers.
Under his proposals, the body would be established by Ofcom and have powers to arbitrate over complaints and levy fines of up to £1m.
However, Cameron warned that he had "serious concerns and misgivings" about statutory underpinning for the regulator - something that he feels is not necessary to achieve the report's aims.
The prime minister said that writing the new law would "inevitably" involve setting the parameters of the regulator, and so would be a press law in all but name.
"That is the concern and that is the rubicon that we have to think very carefully before we cross," he said.
But Labour leader Ed Miliband said that the government "should put our trust in Lord Justice Leveson's recommendations" for overhauling press regulation.
Miliband said that Labour believes the judge's conclusions are "measured and proportionate", and warned that there should be "no more last chance saloons".
[Left: Chris Bryant MP / Right: Hugh Grant]
John Whittingdale, the Tory chairman of the Commons culture select committee, backed Cameron in urging caution over imposing legislation on the print media.
He suggested that the new regulatory body could be held to account in the absence of legislation by regular checks from his committee to ensure that it upholds its purpose.
Elsewhere, Cameron said that Jeremy Hunt, the former culture secretary, had been exonerated over his conduct in overseeing the Sky takeover bid.
Labour had suggested that Hunt gave Rupert Murdoch's News Corporation a "back channel' for communications as he reviewed the multi-billion pound proposed takeover, but the criticisms of Hunt were "emphatically rejected" by Lord Justice Leveson.
The prime minister also said that his party had been repeatedly 'smeared' by Labour over its relationship with newspaper publisher News International.
"During the course of this inquiry, a number of serious allegations were made and I want to deal with them directly. First, that my party struck a deal with News International," he said.
"This is an allegation that was repeated again and again on the floor of this House and at the inquiry itself. Lord Justice Leveson looked at this in detail and rejects the allegation emphatically."
In a rare move, deputy prime minister Nick Clegg is to deliver his own statement shortly after Cameron, after they failed to agree on a joint government response.