David Cameron has been told by Harriet Harman to "man up" and deal with press regulation.
Labour's deputy leader said her party wanted to reach agreement on the issue that is dividing the coalition, but not if the Tories "drive a coach and horses" through Lord Justice Leveson's report.
Harman said she was prepared to consider a royal charter
The political parties are at loggerheads over how to implement press reform in light of the phone hacking scandal.
The Conservatives have put forward plans for a 'royal charter' to manage press regulation, similar to the arrangement with the BBC.
But Labour and the Liberal Democrats want to see Leveson, which called for statute to back up a new regulator, implemented in full.
In an interview with the BBC's Andrew Marr programme, Harman said the opposition would "definitely look at a royal charter" but not if the judge's recommendations had been "watered down".
She claimed Labour had "bent over backwards" and hoped the Prime Minister would not be "lent on" by newspaper who are vehemently opposed to state involvement.
In a direct challenge to the Prime Minister, she said: "I think it's now time for him to, you know, man up, step forward and actually say 'yes, we are going to do it' and then we will agree with him and we will support it."
The Tories, who are eager to avoid using new laws to deal with the issue, published their proposals on February 12, and were immediately accused by Labour of 'diluting Leveson'.
Leveson Inquiry
Leveson Inquiry(01 of53)
British actor Hugh Grant arrives to attend the press conference and publication of the Leveson report, based on a major inquiry set up after the phone-hacking scandal, in central London on November 29, 2012. Senior judge Brian Leveson said British press should have a new self-regulatory body underpinned by legislation which would provide 'an independent process to recognise the new self-regulatory body and reassure the public that the basic requirements of independence and effectiveness were met'. AFP PHOTO / CARL COURT (Photo credit should read CARL COURT/AFP/Getty Images) (credit:Getty Images)
Leveson Inquiry(02 of53)
British actor Hugh Grant arrives to attend the press conference and publication of the Leveson report, based on a major inquiry set up after the phone-hacking scandal, in central London on November 29, 2012. Senior judge Brian Leveson said British press should have a new self-regulatory body underpinned by legislation which would provide 'an independent process to recognise the new self-regulatory body and reassure the public that the basic requirements of independence and effectiveness were met'. AFP PHOTO / CARL COURT (Photo credit should read CARL COURT/AFP/Getty Images) (credit:Getty Images)
Leveson Inquiry(03 of53)
Prime Minister David Cameron makes a statement to MPs in the House of Commons in London on Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press. (credit:PA)
Leveson Inquiry(04 of53)
Prime Minister David Cameron makes a statement to MPs in the House of Commons in London on Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press. (credit:PA)
Leveson Inquiry(05 of53)
Prime Minister David Cameron makes a statement to MPs in the House of Commons in London on Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press. (credit:PA)
Leveson Inquiry(06 of53)
Max Mosley speaks to the media after Lord Justice Leveson announced his Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre in central London. (credit:PA)
Leveson Inquiry(07 of53)
Prime Minister David Cameron makes a statement to MPs in the House of Commons in London on Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press. (credit:PA)
Leveson Inquiry(08 of53)
Max Mosley speaks to the media after Lord Justice Leveson announced his Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(09 of53)
Chris Bryant MP carries copies of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(10 of53)
Chris Bryant MP carries copies of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(11 of53)
John Prescott is interviewed on College Green opposite the Houses of Parliament after the Leveson Inquiry is published. (credit:PA)
Leveson Inquiry(12 of53)
John Prescott is interviewed on College Green opposite the Houses of Parliament after the Leveson Inquiry is published. (credit:PA)
Leveson Inquiry(13 of53)
John Prescott is interviewed on College Green opposite the Houses of Parliament after the Leveson Inquiry is published. (credit:PA)
Leveson Inquiry(14 of53)
Chris Bryant MP carries copies of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(15 of53)
Chris Bryant MP carries copies of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(16 of53)
Chris Bryant MP carries copies of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(17 of53)
Chris Bryant MP carries copies of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(18 of53)
Kate McCann (centre) looks on as a spokesman for Hacked Off reads a statement following the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(19 of53)
Kate McCann (centre) looks on as a spokesman for Hacked Off reads a statement following the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(20 of53)
Kate McCann (centre) looks on as a spokesman for Hacked Off reads a statement following the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(21 of53)
Kate McCann (centre) looks on as a spokesman for Hacked Off reads a statement following the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(22 of53)
Kate McCann (centre) looks on as a spokesman for Hacked Off reads a statement following the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(23 of53)
Lord Justice Leveson delivers his findings into the Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre in central London. (credit:PA)
Leveson Inquiry(24 of53)
Lord Justice Leveson delivers his findings into the Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre in central London. (credit:PA)
Leveson Inquiry(25 of53)
Lord Justice Leveson delivers his findings into the Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre in central London. (credit:PA)
Leveson Inquiry(26 of53)
Lord Justice Leveson delivers his findings into the Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre in central London. (credit:PA)
Leveson Inquiry(27 of53)
Lord Justice Leveson delivers his findings into the Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre in central London. (credit:PA)
David Cameron(28 of53)
British Prime Minister David Cameron leaves 10 Downing Street to make his way to the House of Commons to make a statement on the result of Leveson Inquiry, London, Thursday, Nov. 29, 2012. Lord Justice Brian Leveson released Thursday his report, after a year long inquiry, into the culture and practices of the British press and his recommendations for future regulation to prevent phone hacking, data theft, bribery and other abuses. (AP Photo/Sang Tan) (credit:AP)
David Cameron(29 of53)
British Prime Minister David Cameron leaves 10 Downing Street to make his way to the House of Commons to make a statement on the result of Leveson Inquiry, London, Thursday, Nov. 29, 2012. Lord Justice Brian Leveson released Thursday his report, after a year long inquiry, into the culture and practices of the British press and his recommendations for future regulation to prevent phone hacking, data theft, bribery and other abuses. (AP Photo/Sang Tan) (credit:AP)
Leveson Inquiry(30 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(31 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(32 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(33 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(34 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(35 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(36 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(37 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(38 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(39 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(40 of53)
Lord Justice Leveson with the Report from the Inquiry into the Culture, Practices and Ethics of the Press inside the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(41 of53)
Protesters outside for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(42 of53)
Protesters outside for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(43 of53)
Protesters outside for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(44 of53)
Protesters outside for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(45 of53)
Protesters outside for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(46 of53)
Bob and Sally Dowler arrive for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(47 of53)
Bob and Sally Dowler arrive for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(48 of53)
Kate McCann arrives for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(49 of53)
Kate McCann arrives for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(50 of53)
Kate McCann arrives for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
Leveson Inquiry(51 of53)
Kate McCann arrives for the announcement of Lord Justice Leveson's Report from the Inquiry into the Culture, Practices and Ethics of the Press, at the QEII Conference Centre, in central London. (credit:PA)
MPs warn PM over Leveson report(52 of53)
File photo dated 28/07/11 of Lord Justice Leveson. Prime Minister David Cameron faces fresh demands to reject statutory regulation of newspapers as he prepares to take delivery of the Leveson report. (credit:PA)
COURTS Axe(53 of53)
Mr Justice Leveson who will be the judge in the Anthony Walker murder trial at Liverpool Crown Court, Tuesday November 15 2005, where the two men accused of bludgeoning Anthony to death with an axe go on trial. Paul Taylor and Michael Barton, aged 20 and 17, allegedly attacked the 18-year-old in July as he walked through Huyton, Merseyside, with his girlfriend and cousin. See PA story COURTS Axe. PRESS ASSOCIATION Photo. Photo credit should read: Martin Rickett/PA (credit:PA)
So divisive were Leveson's proposals that Nick Clegg and Cameron took the rare step of making conflicting statements to MPs when they were published in November.
Harman claimed MPs were growing impatient for action after the House of Lords voted in favour of using statute.
She added: "So really it's for the Conservatives now to really take this historic opportunity to sort out what has been wrong for decades and we'll support them if they do that."