Responding to Lord Justice Leveson's findings, Kate McCann said the inquiry provided an "historic" opportunity to improve media standards and called on journalists to treat people in the news with "care and consideration".

Other victims of press intrusion also welcomed the senior judge's proposals for stronger press regulation, but expressed disappointment at the Prime Minister's reluctance to introduce them in full.

Mrs McCann, whose daughter went missing on holiday in Portugal in 2007, gave moving evidence to the inquiry about how she wanted to "climb into a hole" after the News Of The World published extracts from her highly private diary.

She said yesterday: "I welcome Lord Leveson's report and hope it will mark the start of a new era for our press in which it treats those in the news responsibly, with care and consideration."

Mrs McCann went on: "I hope the Prime Minister, and all the party leaders, will embrace the report and act swiftly to ensure activation of Lord [Justice] Leveson's recommendations within an acceptable and clearly defined time-scale."

• Cameron's Tory principles are protecting our ancient liberties

  29 Nov 2012

• Let us implement Leveson, without a press law

  29 Nov 2012

• Leveson Report: latest reaction

  29 Nov 2012

• Damian Thompson: compulsory registration of meetings is creepy

  29 Nov 2012

• Dan Hodges: this is not about Milly Dowler - it's a battle for power

  29 Nov 2012

• Mary Riddell: legislate in haste, repent at leisure

  29 Nov 2012

Mark Lewis, the solicitor for the family of Milly Dowler, the murdered schoolgirl whose phone was hacked by the News of the World, said Mr Cameron had failed the victims of phone hacking by refusing to follow the Leveson recommendations.

"Cautious optimism lasted for about 45 minutes and then the Prime Minister spoke and said he is not going to implement a report that he instigated," he said.

It was the disclosure that the News Of The World had illegally accessed 13-year-old Milly's mobile phone voicemails after she went missing in 2002 that prompted the Prime Minister to set up the Leveson Inquiry in July last year.

Mr Lewis said the Dowlers wanted to ensure that other people did not have to suffer the same shocking invasions of privacy they experienced.

"Whether or not there can be a prevention of that sort of abuse of victims in the future remains to be seen because, of course, implementation is all-important and we have to wait to see what happens," he added.

Max Mosley, the former Formula 1 chief who successfully sued the News Of The World for privacy damages over claims that he was involved in a "sick Nazi orgy", said it would be "astonishing" if the Government did not implement the Leveson recommendations.

He said the "very thorough" report was in many respects better than he could have hoped and its proposals would improve the behaviour of the press.

Jacqui Hames, the former police officer and presenter of the BBC's Crimewatch programme whose phone was hacked, read a statement welcoming the Leveson report on behalf of Hacked Off, the campaign group which has lobbied for tougher press regulation.

She said: "These proposals are reasonable and proportionate and we call on all parties to get together to implement them as soon as possible. The press must be given a deadline, the inquiry is over, now is the time for action."

Christopher Jefferies, the retired teacher who won libel damages over newspaper stories published after he was wrongly arrested for the murder of Joanna Yeates, said he would be disappointed if Mr Cameron failed to endorse the Leveson recommendations.

"I will certainly feel let down. I think it will be a complete disaster," he told ITV News.

"The Prime Minister leaves himself open to the accusation that what he is doing is simply once again bowing to illegitimate pressure from a body which does not want to have its power curtailed in any shape or form."