Europe's human rights chief will call for greater protection of media freedom, while warning of the "dangers" of statutory press regulation.
Thomas Hammarberg, the Council of Europe Commissioner for Human Rights, is expected to condemn the recent phone-hacking scandal but insist it should not be used as an "excuse" to impose tighter controls on newspapers.
However, his robust defence of the media, outlined in a report launched on Wednesday, will bolster calls to curtail the power of "media oligarchies" such as Rupert Murdoch's News Corporation. The lengthy document, which addresses the balance between freedom of speech and human rights, comprises analysis from a panel of media experts.
"Together these contributions give an indication that there is a need for stronger protection of media freedom and freedom of expression in Europe today," Mr Hammarberg is expected to say.
The report, Human Rights And A Changing Media Landscape, highlights the "critical role" played by journalists who subject those in power to scrutiny.
Warning against statutory regulation - a possibility brought to the fore by the phone-hacking scandal and the ensuing criticism of the media's embattled Press Complaints Commission - it states: "There are dangers in this. Public outrage is legitimate when the ethics of journalism are abandoned in pursuit of money and political influence, and when the Press exercises power without responsibility, but it is no basis for curtailing media freedom.
"Certainly, there is something to be said for curtailing the power of media oligarchies - of which News Corporation is a prime example - but that needs to be done in the name of pluralism, freedom and respect for privacy. The Murdoch case, disgraceful though it is, should not be used as an excuse to impose heavy media regulation which would inhibit the capacity of investigative journalism."
Mr Hammarberg's report - which offers an overview of the media across Europe - highlights a decline in the scrutiny of power, particularly at local and regional level, amid editorial cuts in a struggling industry. And it suggests reporting standards have been "sacrificed" in the pursuit of commercial objectives.
Agnes Callamard, executive director at Article 19, a group which campaigns for freedom of expression, said: "The media in Europe and around the world is facing technological, political, and economic challenges that are threatening freedom of expression and freedom of the Press. The United Kingdom, currently chairing the Council of Europe, must heed the recommendations outlined in the Commissioner's report."