Hacking - why an apology will not be enough

Never before has the prime minister called in the cameras to make such a swift and abject apology, but that will not be enough to silence the questions David Cameron now faces.

He said it was the wrong decision to give Andy Coulson "a second chance" and to accept "his assurances" about what had happened at the News of the World.

However, that apology suggests that he was simply too trusting of the man he gave a taxpayer-funded job in Downing Street and, with it, access to confidential and sensitive information. It implies that all that went wrong was that David Cameron was too nice or too naive.

What it ignores is why Cameron hired Coulson in the first place and was so resistant to firing him even as evidence of the true scale of the phone hacking scandal emerged.

When Cameron became Tory leader he vowed to keep his distance from the Murdoch empire - to sup with a long spoon. However, long before he reached Number 10 he abandoned that strategy and decided instead to hug them close.

When Coulson was hired by the Tories in opposition in 2007 it was possible to argue that phone hacking was limited to "one rogue reporter" who had gone to jail. However, in the year before the general election the Guardian and the New York Times produced evidence that it had occurred on a much wider scale.

David Cameron could have chosen not to ask his spin-doctor to enter government with him but he chose to ignore the flashing red lights.

He was warned not to by the press pursuing the story, by colleagues, by his coalition partners as well, of course, as the Labour Party.

He argues that that was because Coulson had proved himself to be competent and trustworthy. Others will assert that Cameron was scared to break the link with the former tabloid editor who knew how to reach the parts of the electorate that he could not.

Andy Coulson believes that if he had never crossed the threshold of Number 10 he might not now be facing prison. Without the link to Number 10 the hacking scandal might never have been front page news and the police would never have launched the massive investigation which is now being played out in court.

If David Cameron had simply thanked Coulson for his work in getting him to power but explained that their partnership could not survive he would still be facing embarrassment but not questions about why, as Ed Miliband puts it, he brought a criminal into Downing Street.