Some 42 Conservative MPs and two Tory peers have signed a letter giving their support to the establishment of a new statutory press regulator.
The move comes amid an increasingly feverish debate over the future of press regulation in the weeks appoaching the publication of Lord Justice Leveson's report.
The publishing industry - as represented by the PPA, Newspaper Society, Newspaper Publishers Association and Society of Editors - has shown a united front in opposition to any statutory involvement in press regulation.
But those who support the creation of a new independent regulator, established in law, include: the leadership of the National Union of Journalists, the campaign group Hacked Off, the Media Standards Trust and many journalism academics.
Today's letter, published in The Guardian, states:
"After eight months, 650 witnesses and 6,000 pages of evidence submitted to the Leveson inquiry, we can be clear about two things. Firstly, that a free press is essential for a free society.
"Secondly, that there are fundamental weaknesses in the current model of self-regulation which cannot be ignored (Prejudging the judge, 2 November).
"No one wants our media controlled by the government but, to be credible, any new regulator must be independent of the press as well as from politicians. We are concerned that the current proposal put forward by the newspaper industry would lack independence and risks being an unstable model destined to fail, like previous initiatives over the past 60 years. These concerns are shared by the NUJ."
Press owners group Pressbof has put forward a plan for a reformed system of self regulation. This would involve tying publishers into contracts with the new regulator, including more lay members from outside the industry and giving it powers to investigate and issue fines of up to £1m.
But the Conservatives say in their letter:
"We agree with the prime minister that obsessive argument about the principle of statutory regulation can cloud the debate. Instead we must do what is necessary to create a genuinely independent system. The defamation bill is currently going through parliament with the support of all parties and the newspaper industry. This proves that, when people try, it is possible to make sensible changes to the law.
"We should also keep some perspective: the introduction of the Legal Services Board in statute has not compromised the independence of the legal profession. The Jimmy Savile scandal was exposed by ITV and the Winterbourne View care home scandal was exposed by the BBC, both of which are regulated by the Broadcasting Act.
"While no one is suggesting similar laws for newspapers, it is not credible to suggest that broadcasters such as Sky News, ITV or the BBC have their agenda dictated by the government of the day.
"The worst excesses of the press have stemmed from the fact that the public interest defence has been too elastic and, all too often, has meant whatever editors wanted it to mean. To protect both robust journalism and the public, it is now essential to establish a single standard for assessing the public interest test which can be applied independently and consistently.
"The prime minister was right to set up the Leveson inquiry. While it has been uncomfortable for both politicians and the press, it also represents a once-in-a-generation opportunity to put things right. Parliament must not duck the challenge."
Yesterday Press Gazette published an online poll asking readers whether they support a new independent statutory press regulator or a reformed system of self regulation.
With 276 votes it found a slim majority of 53 per cent in favour of an independent statutory regulator. Some 40 per cent favoured reforming self regulation, with 6 per cent favouring another solution (such as no regulation at all, as is in the case in the US).
The singatories to the Guardian letter are: Lord Fowler, Sir Malcolm Rifkind, Caroline Spelman, George Eustice, Penny Mordaunt, Nadhim Zahawi, Zac Goldsmith, Robert Buckland, Andrew Bingham, Adam Afriyie, Neil Parish, Rehman Chishti, Brian Binley, Jackie Doyle-Price, Stephen Metcalfe, Oliver Colvile, Mike Weatherly, Sheryll Murray, Claire Perry, Gary Streeter, Gareth Johnson, James Morris, George Freeman, Andrea Leadsom, Marcus Jones, Bob Stewart, Nicholas Soames, Guto Bebb, Geoffrey Cox, Crispin Blunt, Angela Watkinson, Gerald Howarth, David Morris, Mark Garnier, Mark Field, Henry Bellingham, Gavin Barwell, Jesse Norman, Chris Skidmore, Nicola Blackwood, Paul Uppal, Simon Hart, Lord Ryder (Richard)