Will the big media companies go along with a new system of press regulation agreed by the three big political parties in talks going on till 2.30 am today ,
The big media groups - News International, Associated Newspapers, Trinity Mirror, the Telegraph, the FT, the Independent, the Express and the Guardian will be under pressure to accept the idea of an organisation established by royal charter .
The sticking point could be whether or not the media companies see the deal as underpinned by statute, as Ed Ball says it is - or not underpinned by statute as David Cameron insists.
The system will be inserted into law in the Enterprise and Regulatory Reform Bill, which certainly suggests "statute."
Newspapers that refuse to comply with the new structure will face a system of exemplary damages.
Kirsty Hughes , chief executive of the free speech campaign group Index on Censorship, criticises the impact on for press freedom in the UK.
She said: "Index is against the introduction of a royal charter that determines the details of establishing a press regulator in the UK - the involvement of politicians undermines the fundamental principle that the press holds politicians to account."
Scotland's First Minister Alex Salmond is said to have been in touch with people in the South for guidance on whether the new deal would eliminate the need for a controversial set of Scotland-only proposals floated last week.
Earlier today the Prime Minister Cameron told MPs the new system would ensure:
* Million-pound fines;
* Upfront apologies from the press to victims;
* A self-regulatory body with independent appointments and funding;
* A robust standards code;
* A free arbitration service for victims:
* A speedy complaints system.
A clause, now accepted by Cameron, has been drafted by the Hacked Off legal adviser Hugh Tomlinson QC as a central part of the deal. .
But the prime minister, who last week opposed a charter underpinned by statute., insisted it wasn't statutory underpinning.
Cameron said, "What it is is simply a clause that says politicians can't fiddle with this so it takes it further away from politicians, which is actually, I think, a sensible step.
"What we wanted to avoid and we have avoided is a press law. Nowhere will it say what this body is, what it does, what it can't do, what the press can and can't do. That, quite rightly, is being kept out of parliament.
"So no statutory underpinning but a safeguard that says politicians can't in future fiddle with this arrangement."
Cameron can claim the device of royal charter – to avoid direct statute – was his, and resisted initially by Labour.
Labour leader, Ed Miliband told the BBC: "What we have agreed is essentially the royal charter that Nick Clegg and I published on Friday. It will be underpinned by statute. Why is that important? Because it stops ministers or the press meddling with it, watering it down in the future.
"It will be a regulator, a system of complaints where the regulator has teeth so they can direct apologies if wrong is done and it is independent of the press, which is so important because for too long we have had a system where the press have been marking their own homework."
He added: "People who revealed MPs' expenses, people who revealed phone hacking, have nothing to fear from what has been agreed.
"I think a free press has nothing to fear from what has been agreed. This is about a press that doesn't abuse its own power and, if that power is abused, victims have a right to redress because, so often in the past when things went wrong – take the case of the McCanns – they felt they had nobody to turn to."
The deputy prime minister, Nick Clegg, claimed the deal was a victory for the Lib Dems and Labour.
He said: "I'm delighted that we've come to a cross-party agreement. I think it's essential that we do move forward with consensus on this. We'll see the details later. But it's pretty well exactly what I hoped for when I published the ideas alongside the Labour party last Friday."
The campaign group Hacked Off is likely to back the deal.
Dr Evan Harris, the former Liberal Democrat MP and Hacked Off associate director, said: "The victims are prepared to accept this compromise. However...we're not saying it is Leveson, but it is near Leveson."
Labour has conceded on the ownership of the press code committee and on the idea of a general purpose clause that would allow the recognition committee to rule that the regulator had failed. There had been concerns that newspapers were going to be able to write their own press code.
The Conservatives have accepted that apologies can be "directed" by the regulator rather than just "required". Lawyers say this is a big difference.
The newspaper industry cannot veto membership of the regulator.
Maria Miller, the culture secretary, insisted there was a clear acceptance by Labour and the Liberal Democrats that the prime minister's royal charter was the right way forward.
She said: "We will not have this extreme force of press law that we would have had otherwise. The clause will sit alongside the charter. It is a no-change clause; there is no statutory underpinning. It is simply stating there can be no change in the future. That is already incorporated in the charter."
Labour's deputy leader, Harriet Harman, said on BBC Radio 4's Today programme: "The [regulatory] framework is set up in royal charter, not by statute...but just to make sure that the royal charter, which is run by the privy council – effectively which is ministers – just to make sure ministers can't tamper with it in the future."
The amendment to the bill, she said, "has a legal underpinning effect because what we don't want is to have a situation where everybody agrees what the rules should be and then the press lean on ministers and ministers water it down".