Matthew Norman: Now is the moment to stop Murdoch

It has many villains and one or two heroes, while its chief victim lies cocooned from the shock that has winded even the world-weariest media cynic like a kick to the solar plexus. But the story of Milly Dowler's mobile phone speaks of infinitely more than the posthumous violation of a murdered schoolgirl by Rupert Murdoch's demons and the visceral revulsion that this has induced.

This is an amorality tale of systemic corruption as insidious, deep-rooted, all-embracing, diseased and destructive as any known to a modern Western democracy. To understand how it came to this – how prime ministers and our premier police force became the enablers of News Corporation's abundant wickedness – you must go back several decades.

When Margaret Thatcher made her Faustian pact with Mr Murdoch in the 1980s, granting him his every heart's desire in return for his unwavering slavish support, she hastened the creation of the monster we see revealed in all its gruesome hideosity today.

In general terms, she gifted him the preposterous media market share he expertly parlayed into a stranglehold over the political elite. In a country without a written constitution, bereft of checks and balances and devoid of oversight, the levers of power are there to be seized by the most ruthless buccaneer in town. This he did with wonted dark genius, coaxing and cajoling, bullying and bribing, to inculcate the near universally received wisdom that without his approval, no party can be elected or prosper in power for long. Once Thatcher had established the precedent of obeisance, it was rigidly and cringingly adhered to thereafter by Mr Tony Blair, the successor but one she begat, and now by his self-styled heir David Cameron.

Specifically, meanwhile, she politicised the police by using them as a political truncheon at Wapping as with the simultaneous miners' strike. In so doing, she placed them in Mr Murdoch's pocket, where they have snugly remained ever since.

Those scouring yesterday's Sun for a full account of the Milly Dowler obscenity will have been disappointed by a page two report barely bigger than the nipples on the facing page. But those who ploughed on to the centre spread found a nicely-timed reminder of the unholy trinity at work. "On Thursday," ran the taster for the Sun's 16th Police Bravery Awards, "Prime Minister David Cameron will welcome the 59 nominees to Number 10 before a glittering awards ceremony at The Savoy." Glittering indeed. How could it be otherwise when the Murdoch press, the police and the PM come together to celebrate the tripartite partnership forged at Wapping?

If the juxtaposition of "police" and "bravery" in a News Corp context acquires a viciously satirical ring, it would trivialise this affair to harp on about the pitiful performance of John Yates, whose primary offence, one likes to think, was naively accepting the assurances of colleagues too timid to risk the wrath of the hand that feeds. Similarly, it feels almost banal to dwell on Rebekah Brooks, whose tenure as News Corp chief executive might not survive a return to a police interview room for the first time since then-husband Ross Kemp, TV's Hardest Man, dobbed her in to the fuzz during a domestic.

The details of who knew what and when are as ghoulishly fascinating as they are undeniably significant. But fixating on the personnel risks obscuring the grander portrait of a system so dominated in absentia by its unconstitutional monarch – two-bit politicians come and go while Murdoch, like the Queen, abides – that its nominal leaders quail in mortal terror of his wrath.

So does everyone else, from the Met upwards. The Press Complaints Commission is the industry's eunuch, while the Tory chair of the Commons media select committee, John Wittingdale, tells us he admires no one in the media as much as Rupert Murdoch. One committee member, Labour's Tom Watson, has been utterly heroic on phone-hacking, in starkest contrast to his leader Ed Miliband – every inch as craven as Jeremy Hunt, the Secretary of State whose rampant personal ambition dovetails so cutely with the PM's wishes over Murdoch's acquisition of a 100 per cent stake in BSkyB.

If Mr Watson's magnificent example inspired others to conquer their fear, we would be on the cusp of a revolution. Just as in the immediate aftermath of MPs' expenses, mass public fury prises open a window of opportunity. Today there is that tantalising sense that we no longer need to tolerate such Murdoch-Government axis powers' outrages as Mr Blair ceding policy on a euro referendum to him, and attending a party at Rupert's daughter's home on the arm of Mrs Brooks; Mr Cameron's covert Christmas kitchie sups at her Oxfordshire home, shortly before waving through the BSkyB deal and abandoning the greatest chance for penal reform in a generation on the say-so of The Sun; the Murdoch titles – The Times, to its eternal shame, alongside the red-tops – saving Mr Blair's hide over Dr Kelly's death in pursuit of its commercially-driven campaign to destroy the BBC.

I could go on and on cataloguing the Murdoch tentacles that spread everywhere, from the trivial granting of lucrative columns to semi-literate former ministers and retired coppers, to Mr Cameron's breathtaking misjudgement in hiring Andy Coulson as his media supremo. If the PM has discovered that the second iron rule of national life is that you cannot get into bed with Murdoch without one day waking to a nasty rash and an embarrassing discharge, he has always known that the first is this: whatever the battle, whatever the terrain and whatever the stakes, in the end Murdoch wins.

Today there is the hope, faint but seductive, of change. Public repugnance on this scale is a rare and precious force in a country beset by apathy. It fades very quickly, and must be harnessed and deployed before it does.

It would take cross-party unity on a scale seldom witnessed outside time of war, with all three leaders agreeing that this, finally, is the moment to take up Vince Cable's rallying cry and go to war with Murdoch to break his dominion. A full independent inquiry into News Corp's internal workings should be as automatic as one into the Met's scandalous collusion by lethargy. So, needless to add, should an instant reversal of the green light on the BSkyB deal. It beggars all belief that the take-over might still be permitted. It will be a staggering, transcendent disgrace, after this, if it is.

Murdoch has never been as vulnerable as today and, if allowed to wriggle free, never will be again. This is an historic opportunity for parliament to excise the most aggressive malignancy in the body politic these past three decades, or at the very least stop it growing.

Doing so would not mean that Milly Dowler did not die in vain. It would be insufferably glib to suggest that. But it would honour the memory of her name if something wonderful could be salvaged from an unspeakable tragedy that meant no more to Murdoch's minions, as ever working to the Fuhrer in whose image they are cast, than another opportunity to cash in.