An emergency appeal asking for "partisan" government advisers to be excluded from those given advance access to key witness statements and documents at the Leveson Inquiry will be considered by Lord Justice Leveson.
This week, with the inquiry hearing potentially controversial evidence from both the former editor of the News of the World, Andy Coulson, and News International's former chief executive, Rebekah Brooks, a group of civil rights lobby groups has demanded that so-called "spads", or special advisers, should not have the right to see, alter or redact witness statements.
Lord Justice Leveson ruled last week that the Culture Secretary, Jeremy Hunt, was disadvantaged by not having prior notice of James and Rupert Murdoch's written statements two weeks ago. The witness statements of Mr Coulson and Ms Brooks – both still on police bail after their arrests last year in connection with phone hacking – could be damaging and embarrassing for Downing Street and David Cameron.
The lobby groups – the Media Standards Trust, Index on Censorship, Full Facts and English Pen – claim the "partisan advocacy" role of spads should mean their ministerial bosses do not give them advanced details of what witnesses are likely to say. Lord Justice Leveson was expected to announce his decision at the start of today's hearing.
Mr Coulson, who will appear tomorrow, became the Conservatives' communications chief four months after he left the NOTW in 2007 following the imprisonment of the paper's royal correspondent, Clive Goodman, and the private investigator engaged to hack phones, Glenn Mulcaire. Last year he resigned from No 10 as the hacking scandal worsened.
Ms Brooks, who will give evidence on Friday, is acknowledged by Mr Cameron as a "close friend". If requested, she will hand over a tranche of emails and text messages that could show how close the business relationship was between the Murdoch empire's UK print business and Mr Cameron.
The bill for any legal advice Mr Coulson is currently taking is being paid out of his own pocket. However, in the High Court yesterday he was given permission to appeal against an earlier court ruling which backed News International's decision to end payment for Mr Coulson's legal affairs if they related to allegations of criminal activity.
The Master of the Rolls, Lord Neuberger, and Lord Justice Laws said the former editor had an "arguable case" which was expected to be heard before the summer.
News International's legal bill continued to grow yesterday when Mr Mulcaire took phone hacking to the Supreme Court, which will rule onwhether he must disclose who at the News of the World instructed him to hack phones and who he passed the information to.
It will decide if Mulcaire has the right to privilege against self-incrimination and can remain silent on who at the NOTW commissioned him.