Ed Miliband has targeted Rupert Murdoch in his election manifesto speech.
The Labour leader said that voters would have to choose who they wanted in Number 10 when decisions that concern "powerful interests" were being made.
Mr Miliband said "The answer will never be David Cameron."
And you have to ask: who do you want in power when it comes to these big decisions? When the knock on the door comes from the big six energy companies... Or when the phone call comes from Rupert Murdoch. Who do you want in Downing Street? Who do you think will stand up to those powerful interests? Who do you want standing up for you? The answer will never be David Cameron.
Because he’s strong at standing up to the weak, but always weak in standing up to the strong.
Rupert Murdoch's media companies will not face prosecution in America over allegations of phone-hacking and payments to public officials in Britain.
The US Department of Justice had been investigating both News Corp and 21st Century Fox but after completing its probe it said it would not pursue charges.
Gerson Zweifach, representing both companies, said: "We are grateful that this matter has been concluded and acknowledge the fairness and professionalism of the Department of Justice throughout this investigation."
The News of the World newspaper closed as a result and a number of its former journalists have since been convicted following the scandal.
In July last year ex-editor Andy Coulson was found guilty of the hacking plot while his predecessor Rebekah Brooks was cleared of any wrongdoing.
Rupert Murdoch has tweeted that it's "still all to play for" in the Scottish referendum after a poll revealed the No campaign is holding a narrow lead.
New poll disappointing for Salmond, but not a big deal. Still all to play for. But AS had a bad day, promising membership of the EU.
Salmond a friend, great politician, man of the people, etc, but I would be much happier with another great Scottish AS - Adam Smith!
He has tweeted in the past that he is "wrestling with Scottish vote."
Rupert Murdoch has weighed into the Scottish referendum debate, tweeting that the Scots are "better people than to be dependants of London".
Bigger problem! Wrestling with Scottish vote. Scottish Sun No. 1. Head over heart, or just maybe both lead to same conclusion.
Scots better people than to be dependants of London. Hard choice with real pain for some time. Maybe too much.
Rupert Murdoch clutched a copy of The Sun as he left his London home this morning.
ITV News understands the media tycoon is on his way to a staff meeting at News UK, the British newspaper arm of his News Corp company.
Rupert Murdoch has left his central London flat and is believed to be heading to News UK for a meeting with staff, ITV News understands.
The 83-year-old was reading The Sun newspaper as he sat in the front seat of a grey Range Rover.
Murdoch's arrival in the UK follows the acquittal of former News International chief executive Rebekah Brooks on phone hacking charges.
Deputy Prime Minister Nick Clegg has distanced himself from claims by former Cabinet minister Chris Huhne that he was targeted by Rupert Murdoch's newspapers because he called for an inquiry into phone hacking.
Former Energy Secretary Huhne claimed the News of the World hired a private investigator to gain information about an extra-marital affair which ultimately led to the break-up of his marriage after he spoke out about hacking.
Huhne, who left Parliament after being jailed for persuading his then wife to take his speeding points, then accused the Sunday Times of "grooming" his ex-wife Vicky Pryce so she would reveal all about the speeding points.
Speaking at his monthly Whitehall press conference, Mr Clegg - who emphasised the importance of newspapers holding public figures to account - said: "Chris has to speak for himself. All I can tell you is that is his opinion.
"Is it exactly my opinion? No it isn't because, guess what, we're different people. I'm not Chris's keeper."
Former Energy Secretary Chris Huhne has attacked "the Murdoch press" for its role in the speeding points swap scandal which led to the jailing of him and his ex-wife.
Writing in the Guardian newspaper, he admitted that "[his] own behaviour has not helped" but said he believes his calls for the Metropolitan Police to reopen their hacking investigation turned the editors of certain publications against him.
"The News of the World sparked the end of my marriage, but another Murdoch title, the Sunday Times, then groomed my ex-wife until she told them about the speeding points," he said.
Home Affairs Select Committee chairman Keith Vaz wrote to Rupert Murdoch asking him to comment on the secret recording.
In a reply released today, Mr Murdoch said:
I accept that I used the wrong adjectives to voice my frustration over the course of the police investigation.
But I had been hearing for months about pre-dawn raids undertaken by as many as 14 police officers, and that some employees and their families were left in limbo for as much as a year and a half between arrest and charging decisions.
I have no basis to question the competence of the police and I and our newspapers respect the work that they do every day to protect the public.
But I do question whether, over the last two years, the police have approached these matters with an appropriate sense of proportion, and with regard for the human cost of delay.
Rupert Murdoch has reneged on claims the investigation into phone hacking and corruption is "totally incompetent" but said Scotland Yard's probe appears "excessive" and has "gone on too long".
In a letter responding to demands from MPs that the media magnate explain comments he made about police at a staff meeting, he conceded using the "wrong adjectives" to describe his frustration at events over the last two years.
But the News Corp boss also questioned whether officers had "approached these matters with an appropriate sense of proportion" and said it would be unfair to suggest his company had impeded the Metropolitan Police's inquiries.
Mr Murdoch was apparently recorded describing the treatment of journalists who had been arrested as a "disgrace" during a meeting in March and saying that police had been told to obtain court orders to get information, rather than the company offering up material as it had done previously.