You did not have to be a genius to imagine there might have been a statutory element to the proposals brought forward by Lord Justice Leveson. Indeed, the longer the inquiry went on, the more his tone of questioning suggested such a move might happen.

Certainly, by the time David Cameron gave evidence, it was something that could not be ruled out. Given this was his inquiry – something Cameron’s aides were emphasizing last night after his immediate rejection of the most important proposal in the 2,000 page report – he could have indicated his serious misgivings back then, as Michael Gove did for example.

That he did not do so can probably be explained by the fact that at the time he set up the Inquiry his focus was not devising a new system of regulation, but parking the increasingly wretched issue of his relations with senior News International executives. The Inquiry was clearly a panic reaction to get him out of a political hole. Now he is digging another one.

At least with Gove and Boris Johnson, whatever their motives they have been clear through most of their careers, and certainly since Leveson began his work, that any kind of statutory role was a rubicon not to be crossed. No such strong view on grounds of principle has emerged from Cameron, until he set his eyes on the report, saw the word ‘statute’, and decided that mild-mannered and reasonable accusations of betrayal by victims of media abuse and criminality would be preferable to a sustained battering from the press if he went along with Leveson’s plan.His core team, who tend to play to his short-termism when they might be better advised to challenge it, will be scanning the papers today and celebrating the instant reaction. Cameron stands up for freedom, cry headline upon headline. Amid the mix are the voices of the Dowlers and the Watsons and the Milners saying that he made a promise and he broke it. But Cameron and his team will be saying those voices will fade, whereas the papers will churn out their views dressed as news day in day out, and for a while at least, the venom will be slowed for him, quickened for Ed Miliband and Nick Clegg. Politicians being rewarded for pragmatism (provided it suits the vested interests of the press), and punished for adopting positions of principle.

Cameron could not have been kinder to the press. In making his rejection the main issue, he managed to deflect attention from the debate that might otherwise have taken place on the full extent of the depravity of media excess exposed in the report. In indicating that this was suddenly an issue of principle for him, he also removed any kind of meaningful threat should — as history would suggest is likely — the press fail to put together a proper plan for meaningful and tough self-regulation along the lines set out by the Leveson principles.

Having said publicly that there could be no more last chance saloons, and having said privately to the victims that provided the plans were not ‘bonkers’ he would implement them, he has placed a tab behind the bar for as many last chance booze ups as Murdoch, Dacre, et al might fancy. It is possible to agree or disagree with Leveson’s findings, but hard to see anything in there that could be described as bonkers.He now has a media which will play along with the line that the public are bored with all this talk about the press, there are bigger things to worry about, in any event they will behave a bit better for a while, before slowly, steadily reverting to type. Cameron yesterday had the chance to show leadership, as he did over his responses to the Bloody Sunday and Hillsborough Inquiries, but revealed instead that he is very good at doing and saying the right things when talking about other governments, but not when talking about his own. It really is quite hard to respect a Prime Minister who sets up an Inquiry, allows a judge to state in the first paragraph of his report, that he has the personal authority of the PM in the work he has done, and then see that authority taken away before the ink had dried. It leaves people wondering why we had the inquiry in the first place.

Of course, with or without statutory underpinning, there does have to be a new system of press regulation. But if editors and proprietors could not agree with the tame proposals put forward by Lords Hunt and Black (woefully exposed yesterday as spokesmen for the industry rather than voices of the public interest) it is hard to envisage an early coming together around the principles Leveson believes should be part of a new system. The fact that Hunt and Black are even still on the pitch indicates the determination of the industry to ensure it maintains a position of judge and jury of its own actions.

Ed Miliband and Nick Clegg, meanwhile, need to be careful not to fall into the trap Cameron and his media pals will seek to lay for them, where it looks like this is all they care about, when the public continue to care more about jobs, the economy, cuts to public services. But they can take strength from the fact that the public are not stupid, and as the more rabid elements of the press swing behind Cameron, people will know the real reason has nothing to do with policy or principle, and everything to do with Cameron having sacrificed a national interest on the altar of his own fear.

The tragedy is that the fear is misplaced. Media power only exists if they are told they have it. In signalling his fear so clearly yesterday, Cameron has given them another dose of a medicine whose taste they love. The one that wrongly indicates to them that the Prime Minister needs them more than they need him.

But the politics of this is far from over. The latest court appearance yesterday of Andy Coulson and Rebekah Brooks reminded us of the backdrop to all this, and now he has sided with the press against the victims, Cameron is even more closely identified with any fallout from continuing criminal cases and inquiries. Also, just as Miliband and Clegg were shocked by the speed with which the Prime Minister rejected the main proposal, so were some of his backbenchers. I bumped into two of them last night. ‘Pathetic,’ said one. ‘Incredible’, said the other.

They need to hold their nerve. So does Ed Miliband. So does Nick Clegg. Cameron is already indicating he has agreed to a draft Bill being prepared purely to show it is unworkable. He is also indicating that if he loses any kind of vote in the Commons on the issue, he will ignore it. But he will be weakened by it. Because the headlines today tell him he was being strong, he may even feel stronger. In truth it was an act of weakness, and as the debate develops one he might yet regret.