The Hacked Off campaign, which represents many victims of newspaper intrusion, said Lord Justice Leveson had given the Prime Minister a "workable, proportionate, reasonable solution" to the problems of press abuse.
But the group added that David Cameron "had not done his job" by failing to accept the full recommendations of the report and was wrong to trust Editors to "behave themselves".
More top news
World Superbike champion and TV presenter joined thousands of other bikers at an event to raise money for the Midlands Air Ambulance.
Spring takes a hike - for the time being
A number of Britons are feared stranded on Mount Everest after the Nepal earthquake triggered a deadly avalanche on Saturday.