Madeleine McCann's father will challenge ministers today to ensure a new system of press regulation is backed by law.
Gerry McCann, who was paid damages by several newspapers over reporting of the case of his missing daughter, will say he and his wife Kate "had the misfortune to suffer from everything the press could throw at us".
McCann, whose three-year-old daughter vanished from a Portuguese holiday apartment in May 2007, will add: "The reason we subsequently agreed to the ordeal of giving evidence to the Leveson Inquiry was that we don't want anyone else to have to go through what we went through.
"The Leveson package, including the legal underpinning, is the minimum acceptable compromise for us, and judging by the polls, for the public at large too. Leveson without the law is meaningless.
"When the Prime Minister promised to protect those who have been 'picked up and thrown to the wolves' by this process, we hoped for real change.
"The idea that Kate and myself, and the other victims, might have relived our darkest days in the full glare of the media, for no good reason, is just galling."
McCann will speak out after a new poll indicated that most voters are in favour of statutory backing for a new press regulator, as recommended by Lord Justice Leveson in his report on the press.
Some 53 per cent felt statute was necessary if the new regime was to be effective and independent, while 23 per cent thought legal backing would put at risk the freedom of the press, the YouGov survey for the Media Standards Trust found.
Asked whether Lord Justice Leveson's proposals for reform should be implemented, almost three-quarters (74 per cent) said they should while 9 per cent said they should not.
However, more than half of respondents said they had followed the issue either "not very closely" or "not at all".
The poll was released as the Government prepares to publish a draft Royal Charter this week that ministers want to use instead of legislation.
David Cameron has set his face against using statute to underpin regulation, arguing that it would "cross the Rubicon" after centuries of press freedom.
The YouGov poll showed that only 35 per cent of voters would have confidence in a new regulator that was backed by Royal Charter. A regulator set up by the Government - rather than the newspapers - and backed by law would have the confidence of 54 per cent.
McCann will be keynote speaker at a conference in Westminster today where victims of media intrusion will be joined by shadow culture secretary Harriet Harman and Liberal Democrat Justice Minister Lord McNally.
Culture Secretary Maria Miller has also been invited to the event, organised by the campaign group Hacked Off.