The plan was unveiled last month following a cross-party deal at Westminster but not a single national or regional newspaper publisher has so far agreed to sign up to it.
Now the World Association of Newspapers and News Publishers and the World Editors Forum (WAN-IRFA) has written to Mr Cameron urging him to withdraw the idea.
It warned that any form of statutory regulation of the press in the UK will have a ‘chilling effect’ on press freedom in other countries, particular those where oppressive regimes hold sway.
The letter has been written by Jacob Mathew, president of the World Association of Newspapers, and Erik Bjerager, president of the World Editors Forum.
They wrote: “The proposed Royal Charter on Self Regulation of the Press in its name is misleading, given it does not stand alone, but instead interlocks with the Crime and Courts Bill and the Enterprise and Regulatory Reform Bill currently before parliament, which together can not be described as anything other than statutory regulation of the press.
“We believe the issues that prompted the Leveson Inquiry should, and are being dealt with by the criminal justice system. WAN-IFRA does not believe these abuses are cause for additional statutory regulation of the press.”
“WAN-IFRA stands firmly behind the need for a strong and independent press in the United Kingdom, underpinned by an effective self-regulatory system independent of both the state and the newspaper and magazine industry. We urge you to withdraw the proposed Royal Charter and commence a dialogue with all stakeholders as soon as possible.”