David Cameron is facing a major storm over the Leveson report, with deep divisions emerging in the coalition and his own party.
The Prime Minister issued a plea for political consensus on reforming newspaper regulation ahead of the judge's conclusions being published on Thursday.
However, the Liberal Democrats immediately suggested they may refuse to allow Mr Cameron to make a sole response on behalf of the Government.
Conservative MPs are also ranged against each other amid speculation that Lord Justice Leveson will back statutory regulation of the press. Half-a-dozen advance copies of the report have been delivered to Downing Street, with Mr Cameron and his Lib Dem deputy Nick Clegg poring over the weighty document - which sources say is 2,000 pages long and highly detailed - and trying to agree a joint approach.
Mr Clegg is reportedly ready to support the rapid creation of a regulator with statutory underpinning, a move that would be implacably opposed by many Tories, and Mr Cameron is thought to be resisting.
Aides have asked Speaker John Bercow whether Mr Clegg can make a separate statement to MPs if no deal has been struck by the time the premier gets to his feet at 3pm on Thursday. Mr Bercow's office said it is ready to accommodate the request. A final decision will not be taken until senior ministers from both parties meet just before the report is published.
The regulation issue was repeatedly raised as the Prime Minister took questions in the Commons this lunchtime - before he began studying the document. "This Government set up Leveson because of unacceptable practices in parts of the media and because of a failed regulatory system," he said.
"I think we should try and work across party lines on this issue, it is right to meet with other party leaders about this issue and I will do so. What matters most I believe is that we end up with an independent regulatory system that can deliver and in which the public have confidence."
Labour leader Ed Miliband welcomed Mr Cameron's commitment and insisted he wanted "real change". "I hope we can work on an all-party basis. This is a once-in-a-generation opportunity for real change and I hope that this House can make it happen," he told MPs.
A senior Labour source said Mr Miliband will receive the Leveson report at 8am on Thursday, and is not expecting to speak to Mr Cameron ahead of his statement.