Rupert Murdoch's media empire must not be allowed to take over BSkyB while the police are still investigating phone hacking at the News of the World, Ed Miliband says.
The Labour leader warned Prime Minister David Cameron that unless he stepped in to postpone the deal, he would force the issue to a potentially-damaging Commons vote.
"He has got to understand that when the public have seen the disgusting revelations that we have seen this week, the idea that this organisation, which engaged in these terrible practices, should be allowed to take over BSkyB, to get that 100% stake, without the criminal investigation having been completed and on the basis of assurances from that self-same organisation - frankly that just won't wash with the public," he told BBC1's Andrew Marr show.
News Corporation chairman Mr Murdoch is due to fly into London to deal with the mounting fallout from the revelation of the scale of the hacking operation.
The final edition of the News of the World went on sale after it was closed down as a result of the mounting scandal - in what Mr Murdoch said was a "collective decision".