By Ian Dunt Follow @IanDunt
Rupert Murdoch's efforts to limit the damage of the phone-hacking scandal by closing down the News of the World appeared to have failed today, as the row deepened significantly.
Andy Coulson, former News of the World editor and director of communications for Downing Street, was arrested on suspicion of corruption and phone-hacking in central London in a move that confirmed the police operation is intent on going after those at the top of the management structure, not just the journalists themselves.
That presents serious difficulties for Mr Murdoch, who wants to protect Rebekah Brooks, News International chief executive, and his son James, chairman of News Corp, from the ongoing scandal.
It is also disastrous for David Cameron, whose efforts to shield himself from the row are complicated by his relationship with Mr Coulson.
This morning, Mr Cameron offered his toughest message to the Murdochs yet, saying that it was a mistake not to have accepted the resignation of Ms Brooks.
"It has been reported she offered her resignation over this and in this situation I would have taken it," he told a hastily convened press conference in Downing Street.
The prime minister is on the ropes over the row, as he struggles to explain why he hired Mr Coulson despite knowing he left his previous job over phone-hacking.
The political storm has forced Mr Cameroon to offer a judge-led inquiry into phone-hacking which will take evidence under oath. The inquiry could very well end up calling Rupert Murdoch himself.
In a worrying sign for the media mogul, whose decisive action yesterday left newsrooms across the country reeling, many commentators branded the News of the World closure a cynical branding ploy which sacrificed journalists in order to save management.
The pressure grew on the government to pause the BSky B takeover process, despite its announcement yesterday that it would be several weeks before media secretary Jeremy Hunt had finished reading all the contributions.
The government insists it is tied into very specific laws passed by the Labour government which limit its rooms for manoeuvre but Mr Miliband and several other MPs are calling for the case to be passed to the Competition Commission.
Others are encouraging Ofcom to step in, either on the grounds that News International managers do not constitute "fit and proper persons" or under privacy regulations.