Oliver Wright: New light is shed on the timing of Coulson's exit

It is one thing to find more hacking at the NOTW, but quite another to find it at The Sun. And that worries Murdoch

(AFP/ GETTY IMAGES)

When Andy Coulson announced he was stepping down as David Cameron's director of communications, the rest of the Downing Street spin operation went into overdrive.

Senior advisers patrolled the lobbies of the House of Commons briefing journalists that it was wrong to suggest there were new allegations that had led to his departure. He had simply had enough of the pressure, they said.

Last night the dam burst. Only two working days have passed between Mr Coulson's departure and News International's "discovery" of "significant new evidence" on the phone hacking at the News of the World which it has now passed to police.

This is despite News International being aware of the phone-hacking allegations for more than five years. Mr Coulson and Rebekah Brooks, News International's chief executive, are not just former colleagues but they are still extremely close friends.

Mr Coulson owes David Cameron his comeback from disgrace, and it would be strange for him to intentionally keep information from him. Rebekah Brooks herself is close to Cameron – as their Christmas-dinner soirée in Oxfordshire (with James Murdoch also at the table) illustrated.

It doesn't take a conspiracy theorist to join up the dots. So what will be next?

It is clear News International's strategy has changed. Previously it attempted to put up a firewall between itself and Clive Goodman – the only News International journalist to have been convicted of phone hacking – claiming he was one "rogue reporter". It now appears to be admitting that hacking was more widespread.

But don't assume this is a Damascene conversion to openness; it may simply be another firewall. Ian Edmondson has been thrown to the wolves and at some point the company may start admitting guilt in the hacking cases queueing up to be heard at the High Court. And that, it will hope, will be that.

But what worries executives at the company is that the hacking allegations may spread to The Sun, where Ms Brooks was editor at the same time Andy Coulson was at the News of the World.

Talk to any journalist working for a tabloid newspaper at that time and they will tell you quietly that "everybody was doing it" and editors knew about the technique even if they did not know the specifics. Now the police – themselves under fire for their previous lacklustre inquiries – are about to start a fresh investigation under a new boss.

And that's what is worrying Rupert Murdoch. It is one thing to find more phone hacking at the News of the World – quite another to find evidence of phone hacking at The Sun. Especially at a time when he is asking the Government to allow him to buy out BSkyB.

Finally, for the political classes – who themselves suffered the ignominy of the coppers' "knock on the door" over expenses and cash for honours – these latest revelations have resulted in more than a touch of Schadenfreude. Apart from Mr Cameron that is.