Culture Secretary Maria Miller has indicated she hopes to address media concerns about the proposals with a revised charter produced by Friday but a source said there had been no breakthrough.
Mrs Miller, her Labour counterpart Harriet Harman and Liberal Democrat Lord Wallace will continue their negotiations today, with the prospect of the original charter being put forward to the Privy Council if no changes can be agreed .
The source said: "Labour and the Liberal Democrats are very reluctant to make any changes that make the charter more workable for the industry. But we think we will convince them. We are confident that we will get there by Friday."
The Conservative source said Labour and the Lib Dems had been "dragged to the table kicking and screaming" but with further talks scheduled there was hope of progress.
If no cross-party agreement with is reached by Friday, Mrs Miller has indicated she will press ahead with the version of the charter agreed at a late-night meeting over pizzas in Westminster on March 18 in the presence of campaign group Hacked Off.