THE debate over Lord Justice Leveson's call for statutory regulation of the press has unfortunately turned into a political bun-fight.

Labour are so eager to court popularity by hammering the gutter press that they've embraced the Leveson laws with hardly a moment's pause. Meanwhile, from the opposing camp comes the din of grinding axes as special interests led by the Murdoch press line up behind David Cameron against Leveson's "statutory underpinning". Many believe the PM is only opposing regulation because he wants to keep the press barons on-side for the next election.

But while politicians are always guilty of courting the press – even our own First Minister, Alex Salmond, couldn't resist offering to bat for Rupert as Leveson pointed out acidly – we should give the Prime Minister some credit for having genuine reservations about the rush to reintroduce regulation after 300 years. And yes, I know regulation doesn't mean "political control" – but you have to look at how this new "independent" regulator would work.

Let's imagine that the Leveson proposals are adopted into law. What happens then? Well, the new Press Standards Commission (PSC) is appointed by a panel overseen by the communications industry watchdog regulator, Ofcom. Since Ofcom is appointed by Government, a line of influence is already open. The PSC drafts a code of conduct requiring journalists to behave properly, not hack phones, not harass famous novelists, not tell lies about people who have lost children, not blag medical records of politicians' children from the NHS – in other words: obey the law.

But since it is the courts that enforce the law, what else would the commission do? How would the commission enforce good behaviour? It would licence the press – it would decide what is a legitimate accredited journalistic operation.

Leveson doesn't use the word "licence", but he does propose a "kite-mark" for reputable organs. In exchange for being licenced, a newspaper would have certain legal protections in defamation and other cases. Leveson says that those who don't play along would have to pay full court costs in defamation actions even if they win the case. So, if Lord X sues for defamation, and the Sunday Herald wins on the grounds that what they have said about him is true, it might still have to pay the costs of the litigation, which could run into hundreds of thousands of pounds.

Licensing raises the whole issue of compliance. Editors would have to show, even before they embark on a story, that they have fully discussed the implications – not just all the possible legal consequences, but whether they are within the commission's code. If they are not, and the story leads to court action, they could effectively lose the protection even if the story is true. So we can already begin to see some of the difficulties this might cause in a fast-moving news environment.

Imagine a journalist gets wind of a story like the scandal of MPs' expenses, by speaking to an official in the Westminster Fees Office willing to spill the beans. The editors would have to say: hold it right there, is this "compliant?" That is, is it in accordance with the commissioner's rules? Have any rules been broken by having even a conversation with a public official that is not recorded? Is there likely to be any breach of the data protection acts and the Official Secrets Act in proposing to handle stolen information? Leveson wants the data protection acts strengthened so that journalists can only hold information on bank accounts, medical records and so on for a specific story. Unfortunately, this isn't how journalism works.

Decisions on breaches of the Leveson laws would be taken ultimately by appointed commissioners. These will be "independent" figures from what is called "the great and the good" – in other words, retired judges, ex-politicians, former editors, academics and probably the odd lay member such as Hugh Grant or even Charlotte Church. And they will all be vetted by Ofcom and the Government before they sit down.

This body will enforce a code, not in the heat of the moment, but in the abstract; in the theoretical world occupied by judges and civil servants. Would they allow money to change hands in order to bring Parliament into disrepute by breaching the confidentiality of MPs and Parliament? I doubt it.

We have seen what happens in the BBC, which is under regulation by an "independent" trust led by Lord Patten, who is appointed by the Government of the day, and is also regulated by Ofcom. Has this led to good journalism in the BBC? Some would say it has. But it has also led to a BBC run by play-safe bureaucrats who spend their time covering their bottoms, while journalistic standards go out the window as the Newsnight/Lord McAlpine/Savile scandals demonstrated. Regulation is no guarantee of standards. "Referral up" – the watchword of every BBC executive – leads to stifling bureaucracy.

The standards commission would also enforce the right of reply and levy fines (of up to £1 million) for newspapers that transgress – but for what? Presumably for causing "havoc", as Leveson put it, though this is always going to be a difficult thing to define.

It is clear that the McCanns had rather rough treatment at the hands of the press, and no reasonable person could justify the behaviour of the papers which ran unfair and untrue stories about them. But does the body need to be regulated ultimately by Government to ensure balance and right of reply?

However, it may be that this is what the public want. Journalists presume that people want to learn about nasty things going on in Government and in large corporations, but that is an assumption. The BBC has always been held in very high regard by the public, even though it is timid of Government and would never have broken a story like the MPs' expenses revelations. People rather like to believe that their elected members are indeed honourable and decent. Politicians can argue that, if the press has clearly shown that it cannot regulate itself, then the only other body that can do it is Parliament. The Government is at least elected.

However, there is a further problem with Leveson, which I believe will render his system of regulation impossible: the internet. Leveson has delivered a report on the press as it was 20 years ago. The migration of news and comment to the internet is in full swing, yet Leveson inexplicably exempts the internet from his standards system. His standards watchdog will only regulate the printed press, on the grounds that this is "authoritative", unlike those online publications such as the Huffington Post, Newsnet Scotland, Bright Green Scotland, Caledonian Mercury, Liberal Conspiracy, Left Foot Forward, and literally thousands of bloggers and tweeters.

This will lead to the absurd situation in which stories are circulating widely on the internet, but the regulated press cannot report them. A better way to undermine the authority, readership and finances of the press could scarcely be imagined.

This week Twitter has been alive with more names of alleged celebrity paedophiles, who may or may not be guilty. This makes a nonsense of Leveson and his 2000-page report. It is simply not possible to make a meaningful distinction between libels and lies printed on paper and libels and lies published online. They are both means of communication in the public domain and you can't regulate one without the other.

In agreeing to draft a bill implementing Leveson, David Cameron is presumably hoping that some of this will come out. He hopes to show sceptics that he is not in the pocket of Murdoch, but is genuinely concerned that we should understand what regulation actually means. And to remind people that once a bill is on the statute books it can and almost certainly will be amended – like the Data Protection Act. A press that is overseen by retired judges is not going to be able to talk truth to power. Having press licensed by the state will hasten the migration to the internet, which has none of the traditions and skills of the conventional media.