The Labour Party conference was urged today to call on James Murdoch to stand down as chairman of BSkyB in the wake of the phone-hacking scandal.
Unite general secretary Len McCluskey pressed for a "long overdue" review of the rules governing media ownership in the UK.
Labour MP Tom Watson, who played a prominent role in investigating the hacking allegations, won a standing ovation from the gathering in Liverpool for his attack on Rupert Murdoch's media empire.
Mr McCluskey attacked previous Labour leaders for getting too close to Mr Murdoch's News International papers, saying there should be an "element of shame" for the party.
He said: "There is no one in this hall, or indeed in the country, who will not have felt revulsion at the revelations of this summer regarding the activities of News International journalists.
"For our party, there should also have been an element of shame because for years we were complicit in propping up Murdoch's power."
He added: "We shouldn't have waited until the revelations that his papers were hacking the phones of murdered schoolgirls to have recognised the poison in our midst."
In an attack on Tony Blair, he said: "The Labour Party needs to learn lessons - and they won't be learned by standing down by the banks of the Jordan blessing Murdoch's children.
"They will be learned by setting up the two commissions called for in this motion. One is for an overdue look at the rules controlling media ownership and the unacceptable concentration of power, of which the Murdoch empire is the worst example.'
"And the second is to look at a still wider question - how independent trade unions are essential in ensuring that the rich and powerful do not get it all their own way. That they do not control our politics without the slightest counter-balance in society as a whole."
Mr Watson said: "Let's tell Ofcom what we think about James Murdoch. I wouldn't put him on the board of an ornamental garden.
"He's certainly not a fit and proper person to chair a major broadcaster."
Mr Watson, a member of the Culture Select Committee, compared the Sun's coverage of the Hillsborough tragedy to the phone-hacking row which led to the closure of the News of the World.
He said: "Why have those Hillsborough families still not received the justice they deserve? Police failure, a newspaper out of control, politicians failing to act.
"After two years of investigating, I can tell you how the hacking scandal happened: a newspaper out of control, police failure, politicians failing to act. It's the same.
"When he saw what the Sun did, the lies they invented about Liverpool fans stealing from the dead, Rupert Murdoch could be in no doubt, if ever he was, what went on at his newspapers."
He alleged that hacking was not just confined to the News of the World and said Labour had allowed the Murdochs to become "too powerful".
Mr Watson called for Lord Leveson's inquiry into the scandal to call in private investigators who worked for newspapers.
"What is clear is that this isn't just about one rogue private investigator and one form of covert technical surveillance, it's much wider than that," he said.
"I think he needs to understand, before he can act, just exactly how these private investigators worked in the name of a free press that subcontracted illegality and did terrible things."
He also said the inquiry should establish the limits of regulation to replace the "toothless, inadequate" Press Complaints Commission.
Last night Labour leader Ed Miliband pledged to work with Hollywood star Hugh Grant on media reforms.
The actor, who has become a champion for the Hacked Off campaign that is pressing for tougher sanctions and restrictions on the press, claims some newspapers will be "back to their old tricks" soon and questioned whether Labour MPs would still stand up to the media when the furore had died down.
Grant met the Labour leader last night to press his case at the party's conference in Liverpool.
A senior Labour source said it was an "excellent meeting".
"Ed expressed his thanks for Hugh's work in the Hacked Off campaign and they said they would work together in future."
Mr Watson revealed he was prepared to sacrifice his career to expose the hacking scandal, telling delegates: "It was an easy decision but I had to understand the consequences for me.
"I just thought this company is so vindictive they will destroy my career and I will have to leave politics.
"But I thought it was a price worth paying."
Mr Lewis believed the Leveson Inquiry was a chance for journalists to take "a truth and justice approach".
Meanwhile, Rhondda MP Chris Bryant, an outspoken critic of News International, admitted Labour became too close to the company during the party's 13 years in government.
He told the conference: "There's another scandal that we allowed it to happen - not our finest moment.
"In future we should choose our bed fellows with a little more care."
He added: "We have got to find some backbone ourselves - no longer a creepy-crawly party for the media."
Mr Bryant also criticised witnesses who, he claimed, "lied and lied and lied" to Parliament, telling delegates his research found 486 separate lies to Commons' committees since MPs began investigating press conduct almost a decade ago.
Shadow culture secretary Ivan Lewis said Labour would create "tougher" media ownership laws and a register which could see errant journalists barred from the trade.
Mr Lewis told the conference: "The history of the relationship between this party and the Murdoch press is a complex and tortuous one.
"But what can never be complex or tortuous is the responsibility of politicians to stand up in the public interest without fear or favour."
He paid tribute to Mr Watson, Mr Bryant and Lord Prescott for "exposing the phone hacking scandal".
Setting out his reforms, he said: "Never again can one commercial organisation have so much power and control over our media.
"In the period ahead, Labour will bring forward proposals for new, tougher cross-media ownership laws."
While a free press was "non-negotiable", Mr Lewis said: "With freedom also comes responsibility. Neither the current broken system of regulation nor state oversight will achieve the right balance.
"We need a new system of independent regulation, including proper, like-for-like, redress which means that mistakes and falsehoods on the front page receive apologies and retraction on the front page.
"And as with other professions, the industry should consider whether people guilty of gross malpractice should be struck off."
In a message to Rupert Murdoch, he said: "Your newspapers and Sky TV are popular with millions of British people.
"Some people in our movement might find that uncomfortable, but it's true.
"However - and we should have said this a long time ago - Mr Murdoch: never again think you can assert political power in pursuit of your commercial interests or ideological beliefs.
"This is Britain, Mr Murdoch, the integrity of our media and our politics is not for sale."
He also said it was time David Cameron "came clean" about the appointment of former NoW editor Andy Coulson as his communications chief.