In a speech to Labour's National Policy Forum in Birmingham, Mr Miliband said Mr Cameron "does not stand up to the rich and powerful".
He added that Mr Cameron was tied to outdated and ineffective economic, social and political orthodoxies which are "crumbling before our eyes".
The Conservatives said Mr Miliband "isn't living in the real world".
As the prime minister prepares to attend the G20 summit in Mexico, Mr Miliband said the world needed new economic leadership to deliver a global plan for jobs and growth.
He seized on evidence from the Leveson Inquiry of Mr Cameron's close links with senior figures at News International, including former News International chief executive Rebekah Brooks.
He described the inquiry as a "symbol for what is wrong with our politics" and "a scandal about the way Britain is run".
He urged: "The Murdoch Empire must be broken up."
'Rode the horse'
"This prime minister cannot be the answer. This is a prime minister who sent the texts, he received the texts, he even rode the horse. A prime minister who hasn't learned the lessons. That's why we have a tainted prime minister," he said.
"Tainted because he stands up for the wrong people, like Andy Coulson and Jeremy Hunt. Tainted because he does not stand up to the rich and powerful. And I'm not just talking about Rupert Murdoch.
"Tainted because he cannot be the change this country needs. And he even seems to believe that 'we're all in it together' means country suppers with Rebekah Brooks."
In the speech Mr Miliband said his party's task was to "rebuild Britain" so it works for everyone, and "not just a powerful and privileged few".
Commenting on the economic crisis, he said there needed to be a "decisive shift towards jobs and growth".
"They are stuck with an approach to our country's economy, society and politics that simply does not work anymore: a set of orthodoxies whose time is over, which are now crumbling before our eyes.
"The Tories stand up for the wrong people; they run our country with the wrong ideas; they are both out of touch and out of date."
Describing the next steps in Labour's policy review, Mr Miliband said it would focus on three themes: rebuilding the economy, rebuilding society and rebuilding politics.
He said he believed that workers, management, shareholders and customers need to work together to make companies a success.
Mr Miliband went on to say that "we need to build a society of shared responsibility" - a more equal society built on "care, compassion and looking out for each other, not just on money, market and exchange".
He also said Britain needed a politics "which stands up for the many against the interests of the few, however powerful they are".
Michael Fallon: ''It's extremely hypocritical for Mr Milliband to pretend he was somehow above all this''
Responding to Mr Miliband's speech, Conservative Party deputy chairman Michael Fallon said: "Ed Miliband isn't living in the real world.
"This government has already cleared one quarter of Labour's deficit over the last two years. But his answer to the debt crisis is more spending, more borrowing and more debt.
"Ed Miliband has clearly learned nothing from the mistakes he made as Gordon Brown's right-hand man - that's why he can't be trusted with the nation's finances ever again."
On Mr Miliband's comments about the prime minister's close relationship with News International, Mr Fallon later said: "Labour were just as close to the Murdochs and to try to score cheap points on this issue is rank hypocrisy."