A top British judge will on Thursday publish a key report into a phone-hacking scandal, potentially paving the way for strict new press laws and raising tensions in the coalition government.

Brian Leveson is widely expected to include recommendations for statutory regulation when he publishes his findings from a year-long judicial inquiry into press ethics, presenting a dilemma for Prime Minister David Cameron.

The Conservative party leader is under pressure to follow the advice of the inquiry he set up, but dozens of lawmakers from within his own centre-right party on Wednesday voiced their opposition to any state control of the press.

The report could also spark a row between the Tory party and the coalition's junior partners, the centrist Liberal Democrats.

Lib Dem leader Nick Clegg has requested time to make a separate statement in parliament on Thursday should he disagree with Cameron's position, which will be revealed following the report's publication.

Clegg and the prime minister held a 40-minute discussion about the issue late Wednesday with a senior Lib Dem source saying it was still "too early to say" how things would develop.

Cameron warned Wednesday that the current newspaper regulation system was unacceptable, as he received a copy of the report.

But Britain's oldest political magazine said it would refuse to sign up to any government-enforced regulator system, and other newspapers warned that introducing new laws were a threat to 300 years of press freedom.

Cameron set up the inquiry in July 2011 after the discovery of widespread hacking of voicemails and other illegal practices at Rupert Murdoch's News of the World tabloid, which the Australian-born tycoon then closed down.

The prime minister told parliament on Wednesday he hoped the process would lead to "an independent regulatory system" for the press and called for a cross-party consensus, but did not say if he supported new laws.

"The status quo, I would argue, does not just need updating -- the status quo is unacceptable and needs to change," Cameron said.

There will be a parliamentary debate next week on its recommendations, probably followed by a non-binding vote.

The British press is currently regulated by itself through the Press Complaints Commission, a body staffed by editors which critics say is toothless.

The prime minister's Downing Street office received "half a dozen" advance copies of Leveson's 1,000-page report so that Cameron could prepare his statement, a spokesman told AFP.

More than 80 lawmakers from the three major parties said in a letter published Wednesday that any introduction of statutory regulation would be the biggest blow to media freedom in Britain for 300 years.

"As parliamentarians, we believe in free speech and are opposed to the imposition of any form of statutory control even if it is dressed up as underpinning," said the letter published in the Guardian and Daily Telegraph newspapers.

But 42 MPs from the Conservatives have previously written a letter calling for strong new press laws.

British newspapers are thought to be ready to accept a tougher independent regulator that could hand out big fines but insist that signing up should be voluntary.

The Spectator, a right-leaning political magazine which says it is the oldest continuously published weekly in the English language, said that laws aimed at tackling tabloid abuses could have a "chilling effect" on the rest of the press.

"If the press agrees a new form of self-regulation, perhaps contractually binding this time, we will happily take part. But we would not sign up to anything enforced by government," it said in a leader article.

News International chief executive Tom Mockridge also warned against state-backed regulation but admitted newspapers "need a watchdog with bite and a watchdog with investigative powers."

But actor Hugh Grant, who has spoken out on behalf of victims of phone hacking, called for new laws.

"What people are campaigning for is an end to newspapers being able to regulate themselves, marking their own homework," he told the BBC.

The Leveson inquiry heard eight months of testimony from hacking victims, politicians and media figures.

British police have launched three linked investigations into alleged misdeeds by newspapers, while Cameron's former spokesman Andy Coulson and Rebekah Brooks, former head of Murdoch's British newspaper wing News International, have each been charged with phone hacking and bribery.

Both are former Murdoch newspaper editors.

[Image via Agence France-Presse]