Andy Coulson’s resignation puts a big question mark over the Prime Minister’s judgement. More important, however, is the question of the Murdoch empire’s influence in the British media.

It wasn’t exactly a surprise, but Andy Coulson’s resignation is still a heavy blow for the Prime Minister. As Ed Miliband said in a TV interview, it casts serious doubts over David Cameron’s judgement: The PM has been insisting on giving Coulson “a second chance” ever since he appointed him speaker of the Tories in 2007. Even in the past few weeks, as the clouds started gathering over the Director of Communications at Number 10, Cameron stood by his man.

To recap: Four years ago, a journalist at the News of the World and a private detective were sent to prison for hacking into the phones of members of the royal household. As the paper’s editor, Andy Coulson accepted responsibility, although claimed he had no knowledge of the illegal activities – the culprit was a “rogue reporter”, so the story went. Coulson thought the whole matter was buried, and a couple of months later David Cameron appointed him communications director of the Conservatives.

But in 2009, the Guardian challenged his version of events by claiming that hacking was widespread under Coulson’s editorship and that he knew about it. Crucially, it alleged that Scotland Yard had only half-heartedly pursued the case at the time, apparently because of the close relationship between the newspaper and members of the police force. A year later, the New York Times repeated these allegations in a lengthy report. Towards the end of last year, a number of celebrities who thought they were victims of phone hacking brought civil lawsuits against the paper, which resulted in the suspension of a senior News of the World editor shortly before Christmas. It became ever more improbable that the editor-in-chief was as detached from the phone hacking as he had always maintained. Apparently, the whole thing was getting too hot for the spin-doctor at Number 10, and he pulled the plug.

But the story does not end here. The really big question is whether indeed the police had such a close relationship to the News of the World that they were scared of pursuing the case as thoroughly as they were expected to. That would be very serious. Especially considering the huge influence that the Murdoch empire already exerts in the British media. Murdoch’s News Corporation owns four big newspapers (The News of the World, The Sun, The Times and The Sunday Times) and accounts for 80 percent of the pay TV market. Murdoch’s relationship with New Labour was cosy; and with the Tories it is no different – apparently, the Australian magnate was the second person to visit David Cameron after he had taken over as PM. And with the proposed takeover of BSkyB his influence would substantially increase. Such power in the hands of one corporation should always make us feel queasy. In the hands of Murdoch’s News Corporation with its aggressive right-wing agenda, it would be deeply worrying.