Ex-Deputy Prime Minister Lord Prescott, actor Hugh Grant and dozens of other public figures are demanding an inquiry into newspaper phone-hacking.
It follows allegations that a private investigator working for the News of the World hacked into Milly Dowler's phone.
Mr Grant said people felt "viscerally sickened" by the revelations.
The House of Commons is to debate the calls for an inquiry for up to three hours on Wednesday.
News International, which owns the News of the World, has promised to investigate the claims made against it.
Hacked Off, a campaign supported by Mr Grant, Lord Prescott, Conservative former Health Secretary Lord Fowler, Labour MP Chris Bryant, Liberal Democrat MP Adrian Sanders and the Dowlers' lawyer, Mark Lewis, has started an online petition calling for a full public inquiry.
Police are already investigating allegations over phone-hacking by detectives working for the News of the World, but the group described this as too "narrowly focused". Read on...
And here is Robert Greenwald's interview with the BBC who's done lots of great work documenting Murdoch and his media empire here in the U.S. in their Fox Attacks series.