A "historic opportunity" for press reform could be "squandered" following the end of cross-party talks into regulation, the father of missing Madeleine McCann said.
Gerry McCann said David Cameron was faced with a "binary choice" between newspaper barons or the victims of press intrusion.
His comments come after the Prime Minister yesterday pulled the plug on efforts to reach a cross-party consensus, announcing he will bring the matter to a head by forcing a vote in the House of Commons on Monday.
The dramatic move prompted campaigners to accuse Mr Cameron of a "shameless betrayal of victims of press abuse".
Mr McCann and his wife Kate, whose daughter went missing when the family was on holiday in Portugal in 2007, gave moving evidence during the Leveson Inquiry about their experience at the hands of the media, where Mr McCann described how his wife felt "mentally raped" by the News of the World's publication of her intensely-personal diary.
The coverage of the disappearance of Madeleine was given by Lord Justice Leveson as an example of how stories ran "totally out of control".
In the wake of the dramatic end to cross-party talks, Mr McCann told the Press Association: "What concerns me greatly is that an historic opportunity for press reform may be about to be squandered. Lord Justice Leveson's proposals were measured and modest. They didn't go far enough in my view. But I and other victims of gross press misconduct were prepared to regard them as the minimum acceptable compromise.
"We gave evidence to the inquiry so that some lasting good might come out of a horrendous experience. We want our politicians to protect us, to stand up for the ordinary victims instead of siding with the wealthy and powerful. On Monday, it comes down to a binary choice: the newspaper barons or the people they abused in search of profit. Leveson or more of the same. It is as simple as that."
When the Leveson report was published in November, Mr McCann said if its recommendations on press regulation were not implemented, giving evidence to the inquiry would have been "almost useless".
He urged politicians to "do the right thing" and accept in full the suggestions for a new regulatory system, while his wife said she hoped it would mark the start of a new era for the press, urging Mr Cameron to "embrace the report and act swiftly".