The Government says it is disappointed that newspaper and magazine publishers are to mount a legal challenge over a decision to reject their proposals for a new royal charter to govern the regulation of the press.
The announcement that the industry is to apply to the High Court for a judicial review raises doubts over whether ministers can go ahead with plans to seek the Queen's approval at a Privy Council meeting next week for a rival royal charter, which is backed by the three major political parties but bitterly opposed by much of the industry.
The Queen has already been urged by a group of international press freedom bodies not to sign the charter, and industry sources said the Privy Council should now reconsider its plans to press ahead with approval at the October 30 meeting.
Meanwhile, final plans were published for the establishment of a new Independent Press Standards Organisation (Ipso) to replace the Press Complaints Commission as the industry's watchdog.
The industry group which has drawn up the plans said Ipso could begin work early in the New Year and provide the tough, independent and effective regulator which Sir Brian Leveson called for in last year's report on media ethics and practices.
The Department for Culture, Media and Sport welcomed the progress the industry had made on establishing a new regulator but expressed disappointment at the decision to take legal action.
A spokesman said the industry royal charter had been considered in "an entirely proper and fair way" by a Privy Council sub committee and that Culture Secretary Maria Miller had secured significant changes to the cross-party charter to address press concerns.
"The Government is working to bring in a system of independent press self-regulation that will protect press freedom while offering real redress when mistakes are made," the spokesman said.
"The Culture Secretary pushed hard for recent changes on arbitration and the standards code to be made, which will ensure the system is workable and the stated intention to go to court is particularly disappointing in light of these changes."
A Government source indicated that ministers would wait until the industry has filed papers with the court before deciding how they would respond.
The application for judicial review asks the High Court to quash the October 8 decision by a committee of the Privy Council, made up of Government ministers, not to grant the industry charter.
The Press Standards Board of Finance (PressBof), the industry body which funds the regulatory system, argues that the application was not dealt with fairly, that the Government and Privy Council failed to consult with the press and that the procedures used were "irrational".
PressBof chairman Lord Black of Brentwood said they had decided to take action because of the "enormous ramifications for free speech" in the UK and across the globe.
"The Government and the Privy Council should have applied the most rigorous standards of consultation and examination of the royal charter proposed by the industry, which would have enshrined tough regulatory standards at the same time as protecting press freedom," he said.
"They singularly failed to do so, and that is why - as the issues at stake are so extraordinarily high - we are having to take this course of action."
The rival royal charters are similar in many respects. Both would create a "recognition panel" to oversee an independent self-regulatory body with powers to impose fines of up to £1 million on newspapers for wrongdoing.
However, while the press charter would require industry-wide approval for any amendments, the politicians' version could be changed by a two-thirds majority in Parliament, sparking fears within the industry that future governments could seek to encroach upon media freedom.
It is thought that some newspaper publishers may follow the lead of The Spectator magazine, which has said it will not sign up to any regulator which is endorsed by a recognition panel set up under the Government charter.
More than 80 pages of legal documents underpinning the establishment of Ipso were released by the Industry Implementation Group on a new website, www.ipso.co.uk, following extensive consultations involving lawyers and editors from hundreds of publications.
Paul Vickers, chairman of the Industry Implementation Group and executive director of Trinity Mirror plc, said the industry could now move to establish the "tough, independent, effective regulator" that the then Lord Justice Leveson called for in his report.
"I am confident that what we have produced will be the toughest regulator anywhere in the developed world - one which will guarantee the public the protection it deserves, but which will also ensure we maintain the free press on which our democracy is founded," he said.
The plans, to which a majority of publishers have indicated they are committed, are contained in a series of documents including:
:: A contract which will bind publishers to Ipso and give the regulator tough powers of investigation, enforcement and sanction;
::The regulations under which Ipso will operate, investigate complaints and undertake standards investigations;
:: The Articles of Association which will set out the governance of the regulator and guarantee its independence;
:: The financial sanctions guidance under which Ipso will be able to impose fines of up to £1 million; and
:: The Articles of Association of a new Regulatory Funding Company setting out transparently how Ipso will be funded.
Bob Satchwell, the executive director of the Society of Editors said: "The new body will give the public a clear path to air their complaints while at the same time protecting the freedom of the press that is essential in our democracy."
However Hacked Off, the lobbying group which has led the campaign for tighter press regulation, said the industry's actions were "predictable and self-serving".
"The people leading this part of the newspaper industry are exposing themselves as desperate and deaf," said executive director Brian Cathcart.
"Desperate, because they are now resorting to a legal challenge to something based on the findings of a public inquiry, and backed by the victims of press abuse, all parties in Parliament and the overwhelming majority of the public.
"Deaf, because they refuse to listen to the evidence that there is no threat to the free press and that this deal actually benefits the press, both financially and in terms of freedom of expression."