Nick Clegg has ordered Liberal Democrat MPs not to support David Cameron's decision not to refer Jeremy Hunt to advisers on the ministerial code, in a move that risks causing a major rift in the Coalition government of the UK.
Cameron has come under fire from all sides for his refusal to refer the culture secretary to Sir Alex Allan, the the adviser on the ministerial code, over his actions during the News Corporation bid for control of BSkyB.
The Labour Party will table a motion in the House of Commons calling for Hunt to be referred to Allan and the deputy prime minister's decision will leave Cameron high and dry and could force an embarassing U-turn.
MPs critical of Hunt's actions believe that there needs to be more detailed investigations into the extent that he disclosed his News Corp lobbying before he was given an overseeing, quasi-judicial role with regard to the bid.
When the Leveson inquiry into press ethics released more than 150 emails and messages sent between Hunt's aide Adam Smith and News Corp's Frederic Michel, MPs immediately called for Hunt's resignation over accusations that he had breached his impartiality and instead greased the wheels of the deal.
Cameron and Hunt remained defiant in the face of calls for Hunt to face Allan, claiming that Hunt would clear his name when he gave evidence at the inquiry - despite Lord Justice Leveson making it clear that is was not within his remit to consider breaches of the ministerial code.
Although many were left unsatisfied by Hunt's answers to the inquiry, Cameron immediately announced that he was happy that the controversy was resolved.
MPs still want more information over how far Hunt allowed, or even directed, Smith to maintain contact with News Corp. Although Hunt spoke out in support of Smith, who resigned shortly after the emails were disclosed, several critics see him as a sacrificial lamb.
When Smith spoke to the inquiry he revealed that he had been given no real direction or warnings over the suitability of his contact with Michel.
Clegg's decision comes on the day he is due to give evidence to the inquiry. His plans not to back Cameron appear to signal him distancing himself News International and avoid his name being added to the list of red-faced cabinet members struggling to explain their proximity to the media empire.
Brooks due in court
As MPs fight over one aspect of alleged media malpractice in the commons, former News International cheif executive Rebekah Brooks will begin her court battle on three charges of conspiring to pervert the course of justice.
Brooks faces the court along with her husband, Charlie, and four other former colleagues, all of whom face a single charge at Westminster Magistrates Court.
The charges arose following police investigations into Operation Weeting and are based around allegations that the accused conspired to hide documents and material from the police investigation.