Rival plans for press regulation have been set out ahead of a Commons showdown after David Cameron pulled the plug on cross-party talks.
Labour and the Liberal Democrats joined forces to publish a "strengthened version" of the Prime Minister's proposed royal charter to establish a new watchdog.
They signalled they still believed legislation was required to underpin an independent self-regulatory body as recommended by the Leveson Inquiry into phone hacking. That leaves them firmly at odds with Mr Cameron who believes that would threaten press freedom and make the system unworkable as newspapers would refuse to sign up.
MPs will choose between the two approaches in a series of votes on Monday. The premier faces a tough battle however, with his Lib Dem deputy and Opposition leader Ed Miliband wooing Tory backers of tougher regulation to their cause. Publication of the rival draft royal charters in quick succession this afternoon exposed the main remaining areas of difference between the two sides.
Mr Miliband said the Lib/Lab version differed from the Tory plan in three crucial respects: "First, this must be an enduring settlement. That means underpinning the charter with the minimum amount of legislation needed to guarantee its success and independence over time. We want to ensure that future governments cannot tamper with the new system, either by watering it down under pressure from the newspapers, or introducing new draconian measures which would threaten the freedom of the press.
"Second, the regulator should be properly independent of the press, so we would remove the industry's power of veto over appointments. Finally, when wrong is done, the regulator should be able to investigate, as well as ensure a proper and prominent apology is made."
Mr Clegg said it was "a strengthened version of the Royal Charter that can deliver what Leveson wanted" and should reassure both press and victims. "I hope the approach we are publishing today plots a middle course between the dangers of doing nothing and the fears some people have of a full-scale legislative approach," he said.
MPs will vote on Monday on an amendment to the Crime and Courts Bill which would enable the courts to impose "exemplary damages" in libel cases and other civil actions on newspapers which have not signed up to the regulator.
Mr Cameron regards the measure as essential to his scheme by acting as a spur to newspapers to sign up to a regulator system he says would be the toughest ever in Britain. Allies acknowledged there was a "strong chance" it would be defeated however, as the Tories have no overall majority in Parliament and are opposed to their coalition partners.
Shadow culture secretary Harriet Harman said she hoped cross-party agreement could still be reached ahead of Monday's votes - warning the press could exploit political divisions not to sign up to any new system.