A media group alliance has said it is "fanciful" to hope Sky News will be kept independent under Rupert Murdoch's bid to take full control of BSkyB.
The coalition - including BT, Guardian Media Group, Associated Newspapers, Trinity Mirror, Northcliffe Media and the Telegraph Media Group - argued that Culture Secretary Jeremy Hunt's plans to wave through the News Corp takeover are flawed.
In a legal submission to the Department for Culture, Media and Sport (DCMS), the group said Mr Hunt's proposed decision breaks precedent and goes against regulatory advice, claiming News Corp's undertakings will not address media plurality concerns.
But details of the submission follow a Financial Times report yesterday suggesting the alliance has privately admitted it has virtually no chance of success in blocking Mr Murdoch's plans.
It is thought they have not been able to reach agreement on whether to go ahead with a judicial review, although the alliance is not said to have reached a decision yet.
Mr Hunt said earlier this month he was minded to back News Corp's proposals to spin off Sky News as part of any deal to buy the remaining 61% in BSkyB it does not already own. The media giant offered to make the channel into a separate independent company and subsidise it for a decade.
Mr Hunt launched a 15-day consultation on the undertakings before making his final decision, with the deadline yesterday.
The media alliance will have three months from the final decision to launch a judicial review.
Its submission claims the planned Sky News spin-off does not address Ofcom's main objection - that the deal would reduce media diversity - saying it would remain financially dependent on BSkyB.
"It is fanciful to expect that Sky News will enjoy any meaningful independence allowing it to offer a separate contribution to news plurality," said the submission.
The DCMS said it received more than 38,000 responses to the consultation.
Lord John Prescott has sent a letter to Mr Hunt, calling on the Government to delay its decision until inquiries into the phone hacking investigation at Mr Murdoch's News Of The World are completed.
And results of a survey yesterday commissioned by campaign network Avaaz suggested an overwhelming majority of Britons oppose News Corp's move for BSkyB.
Almost 60% of respondents said Mr Murdoch had too much influence on British politics, while 64% said the merger will give News Corp and Mr Murdoch too much power over the media.