The House of Lords has turned down a petition for permission to appeal in the privacy battle between Canadian folk singer Loreena McKennitt and Niema Ash, the former friend who wrote a book about her.
The Law Lords rejected a petition from Ms Ash seeking to appeal against the decision of the Court of Appeal to uphold the original judgment by Mr Justice Eady that parts of Ms Ash's book, published by a company she owns, breached Ms McKennitt's privacy, and that it was also a breach of confidence.
The House of Lords Appeal Committee rejected the petition because it "does not raise an arguable point of law of general public importance which ought to be considered by the House at this time".
The House of Lords' decision, announced yesterday, was welcomed by Mark Thomson, a partner with solicitors Carter-Ruck, who represented Ms McKennitt.
"It is probably the most important decision for 20 years," he said.
"This is a landmark decision for protection of privacy in this country.
"With an intense focus on the facts of the case at trial Mr Justice Eady performed a proportionate balancing exercise on the parties' respective rights.
"The judgment has helped define the breadth of privacy rights, the relevance of accuracy in the material disclosed and the extent to which the public interest is truly served by mere curiosity."
Ms McKennitt said: "I am very grateful to the courts, including the House of Lords, the Court of Appeal and Mr Justice Eady who have recognised that every person has an equal right to a private life.
"If an aspect of career places one directly in the public eye or if extraordinary events make an ordinary person newsworthy for a time, we all still should have the basic human dignity of privacy for our home and family life.
"As an artist I naturally feel strongly about freedom of expression, and I feel vindicated that the law supported my view that freedom comes with responsibility for decency, fairness and truth."
Ms Ash, who had represented herself at the original trial, which was held in private, said she was "devastated" by the House of Lords'
decision, which she felt had ignored major legal issues.
She would now seek to take the case to the European Court of Human Rights, she said, adding: "David Price had put together an excellent argument, and I cannot understand how the House of Lords can say there was no major issue to consider."
Hugh Tomlinson QC, of Matrix chambers, a leading expert on privacy law, said: "It is very significant that the House of Lords have refused permission to appeal.
"This means that radical new developments in privacy law established by that case are now firmly established.
"In practice, the decision in the Flitcroft case has now been succeeded, and public interest is narrowly confined.
"The distinction between true and false private information is now of little or no significance.
"The House of Lords' decision means that the very strong privacy protection given the Court in McKennitt is now firmly established in English law," Mr Tomlinson added.
Gill Phillips, a solicitor at Times Newspapers, which was one of a consortium of media group which attempted to intervene in the case when it reached the Court of Appeal, said: "It is disappointing that the House of Lords has not taken the opportunity to explore what the media regard as some crucial matters on where the law of privacy is going."
The petition for permission to appeal, which was lodged on January 19 by David Price Solicitors and Advocates, which represented Ms Ash in the Court of Appeal, argued that the decisions by the lower courts represented "a significant shift in favour of privacy at the inevitable expense of freedom of expression".
It argued that the Court of Appeal's decision could not be reconciled with its own liberal approach in the Garry Flitcroft case, A v B plc, which for all practical purposes had been overruled.
Media groups see the decision as opening the gates for the courts to issue more pre-publication injunctions, with wider effects.
The case also suggests that publication of private information about public figures will be allowed only if it makes a contribution to a debate of public importance, irrespective of whether the information is already in the public domain.
By conflating defamation and privacy, the decisions at first instance and in the Court of Appeal also seem to open up for the courts a possible way to by-pass the long-established rule in Bonnard v Perryman, which prohibits prior restraint on publication of material a claimant says is defamatory if the defendant intends to plead justification.
Media law observers say they fear that many personalities will now try to argue that news organisations and others intend to publish "false private information" about them, thus giving the court a route by which to issue an injunction, rather than to claim that they intended to publish defamatory material, which would not.
Many celebrities go to court, they say, not to protect their reputations, but in order to safeguard their public images from publication of material which might show them in a bad light.